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Edexcel ScienceiGCSE Physics

U.Electrostatics

2019-2020

Name:________________Physics Teacher:______________

House CG

Year 11

Specification Checklist

2.01 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s),

2.22 identify common materials which are electrical conductors or insulators,

including metals and plastics

2.23 practical: investigate how insulating materials can be charged by friction

2.24 explain how positive and negative electrostatic charges are produced on

materials by the loss and gain of electrons

2.25 know that there are forces of attraction between unlike charges and forces

of repulsion between like charges

2.26 explain electrostatic phenomena in terms of the movement of electrons

2.27 explain the potential dangers of electrostatic charges, e.g. when fuelling

aircraft and tankers

2.28 explain some uses of electrostatic charges, e.g. in photocopiers and inkjet

printers

Electrostatics – Science (Physics) 2

Key Words

Key Word Image Definition

Charges Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges; positive and negative (commonly carried by protons and electrons respectively).

Conductor An object or type of material that allows the flow of an electrical current in one or more directions

Earthing (Grounding)

The process of removing the excess charge on an object by means of the transfer of electrons between it and the Earth.

Electrons A fundamental particle with negative electric charge

Electrostatic Force

Attraction or repulsion of particles or objects because of their electric charge

Friction The force that opposes the motion of an object

Insulator A material whose internal electric charges do not flow freely

Van de Graaff generator

A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column


https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjX6Yz47a_dAhWxz4UKHXXBCrYQjRx6BAgBEAU&url=https://learn.sparkfun.com/tutorials/what-is-electricity/flowing-charges&psig=AOvVaw1XvgwIFyOsVdYd4-RXeCKz&ust=1536649050135524

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwi665yP7q_dAhVOhxoKHVmNB-YQjRx6BAgBEAU&url=https://physics.tutorvista.com/electricity-and-magnetism/ohm-s-law.html&psig=AOvVaw0HGE1-2iQCSsDNuKAnD84K&ust=1536649093512606

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https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwj0ocjm7q_dAhWSx4UKHZv7AQgQjRx6BAgBEAU&url=http://agaus.com.au/product-category/rigid-electrical-insulation-materials/&psig=AOvVaw3OgNWTNfDvAmKLMoQej-aQ&ust=1536649276509773

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjjlLj27q_dAhWHy4UKHSQLD9cQjRx6BAgBEAU&url=https://www.curiousminds.co.uk/van-de-graaff-generator-large.html&psig=AOvVaw3DujNFRgcEUTS59PBIc8YO&ust=1536649312227355

1: Charging Materials

Knowledge and Understanding Quiz

1. What will happen when you put two north poles of a magnet near each other?

……………………………………………………………… (1)

2. Define current.

………………………………………………………………………………………… (1)

3. What is the charge on an electron?

………………………………………………………………………………………… (1)

4. What is charge on a proton?

………………………………………………………………………………………… (1)

5. In what direction does friction act?

………………………………………………………………………………………… (1)

6. What is the equation linking charge, current and time?

………………………………………………………………………………………… (2)

7. Give an example of a conducting material.

………………………………………………………………………………………… (1)

8. Give an example of an insulating material.

………………………………………………………………………………………… (1)

9. In what direction does current flow?

………………………………………………………………………………………… (1)

[Score /10]


Learning Outcomes:

1. Describe the effect of positive and negative charges on the forces of attraction and repulsion

2. Describe how friction can be used to charge an insulating material3. Explain why friction cannot be used to charge a conducting material unless it is

electrically insulated

Attraction and Repulsion of Charges

Key Ideas

1. When we describe electric charges we are referring to positive and negative charges (e.g. protons or electrons)

2. There are forces between these electric charges such that like charges repel and unlike charges attract.

3. We can charge up an insulating rod using friction.


U1: Charging with Friction

In this investigation you are going to use friction to chargeup different materials.

In this investigation the method is written in the questions and will be underlined so it is vital that you work methodically through these.

U1: Method and Questions

1. Hold the polythene rod and cloth next to the small pieces of paper in turn. What do you see happening?

……………………………………………………………………………………………………….

2. Now ‘rub’ the rod with the cloth. What force have you created between the rod and the duster?

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Top Tip: The best way to do this is to hold the bottom of the rod firmly in one hand and grip the rod with the duster about 5 cm from the other end. Pull the rod out of the duster and then repeat.

3. Do you see any change in the rod’s appearance?

……………………………………………………………………………………………………….

4. Touch the end of the rod. Do you notice anything?

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5. Now ‘rub’ the rod with the cloth again. Hold the rod close the small pieces of paper. What happens?

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6. What evidence is there that there is a force acting between the paper and the rod?

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Health and Safety Check!

I may get a small static shock from charged cloth – be aware

7. Repeat the above experiment using the acetate rod (clear rod). Compare your results with the first experiment.

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8. Repeat the experiment using a number of different types of rod and cloths. Does it matter which combination you use?

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9. Use the cloth this time to rub a metal rod and then hold it up to the small pieces of paper. What happens?

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10. What do metals do that none of the other materials in the investigation do?

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*Do not move onto the next section without permission from your teacher*

11. Turn on a tap so that a thin stream of water is visible. Use the cloth to rub the polythene rod.Hold your rod 5cm from the water stream just below the nozzle. What happens?

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12. Slowly move the rod until it is 1cm away from the water. What evidence do you see that a force is acting?

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13. How does the size of this force vary with distance?

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14. What would you expect to happen if you used the acetate (clear) rod instead? Test it!

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What was happening?

Key Ideas

1. When we created friction between the cloth and the rod we transferred electrons to the cloth (it becomes negatively charged), and the rod became positively charged.

2. Because unlike charges attract, electrons in the paper are pulled to the near edge of the paper (towards from the rod)

3. The side of the paper closest to the rod is now negatively charged4. Since unlike charges attract the paper was attracted to the rod.5. Both the cloth and the rod must be electrical insulators. 6. If one of the cloth or the rod is a conductor on the cloth and rod are made of the

same material they will not become charged.


2: Electrostatic Forces

Knowledge and Understanding QuizUse the knowledge from Shell and Remove to answer the following questions:

1. Define centre of gravity/mass?

……………………………………………………………… (1)

2. Give 2 properties that all electromagnetic waves have in common.

………………………………………………………………………………………… (2)

3. Calculate the efficiency of a lightbulb that gives out 650J of Light Energy when supplied with 1200J of electrical energy. .

………………………………………………………………………………………… (3)

4. Sketch the graph of kinetic energy of particles agains temperature (Kelvin)

(3)

5. What is the role of the control rods in a nuclear reactor?

…………………………………………………………………………………………

………………………………………………………………………………………… (1)

Score [ /10]


Learning Outcomes:

1. Describe the effects of electrostatic force2. Explain how a Van de Graaff works.3. Give an example of electrostatic force at work and explain what is happening in

terms of the charges.

Electrostatic Forces between objects

Key Ideas

1. Charged objects can exert forces on other charges objects without being in contact with them since electrostatic force is a non-contact force.

2. If the charges are alike the objects with repel, if they are opposite they will attract. 3. It is possible for a charged object to attract something that is uncharged.4. This is because the charged object causes the charges in the uncharged object to

redistribute5. A good example of this is sticking a balloon to the wall or ceiling.


U2: Van de Graaff demonstration

In this demonstration your teacher is going to be usinga Van de Graaff generator.

How does a Van de Graaff generator work?

Following the demonstration, make notes below on what you saw happening.

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Choose one of the demonstrated phenomena and explain in terms of electrostatic forces what was happening.

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After touching the Van deGraaff you must dischargeon the wooden benches before touching the floor.

Do not attempt to touch any other metal surface while touching the Van de Graaff

Keep phones, laptops andother electronic equipmentaway from the Van de Graaff

Worksheet: ElectrostaticsUse the knowledge you gained in the last 2 lessons to answer the following questions.

Q1.(a) A student uses some everyday items to investigate static electricity.

1 A strip of plastic is cut from a plastic carrier bag

2 The plastic strip is rubbed with a cloth

3 The plastic strip is hung over a wooden rod

(i) Draw a ring around the correct answer in the box to complete each sentence.

Rubbing the plastic strip with a cloth causes the strip to become negatively charged.

electrons

This happens because neutrons move from the cloth onto the plastic strip.

protons

a negative

The cloth is left with a positive charge.

zero

(2)

(ii) When the plastic strip is hung over the wooden rod, the two halves of the strip move equally away from each other.

What two conclusions should the student make about the forces acting on the two halves of the plastic strip?

1 ..............................................................................................................................

2 ..........................................................................................................................(2)


Q2.(a) A company that produces bottles of mouthwash found a problem with the automatic filling system.

As the bottles go towards the filler, the bottles move around on the conveyor belt and become electrostatically charged. This causes the stream of mouthwash to move sideways, missing the open top of the bottle.

The company came up with an answer to the problem. Before the bottles reach the filler, the bottles pass through a stream of ionised air. The ions in the air neutralise the charge on the bottles.

(i) Explain why the plastic bottles became charged.

..............................................................................................................

.............................................................................................................. (2)

(ii) What happens to the structure of an atom to change the atom into an ion?

............................................................................................................... (1)

(iii) Earthing the conveyor belt with a conducting wire would not have solved this problem.Give a reason why.

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...............................................................................................................(1)


Q3.A student rubs an acetate rod with a cloth.

Figure 1 shows the charges on the acetate rod and cloth before and after rubbing.

Figure 1

(a) Explain how rubbing an acetate rod with a cloth causes the rod and cloth to become charged.

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(b) After charging them, the student moves the acetate rod and the cloth closer together.

Which statement is correct?

Tick one box.

There is no force between the acetate rod and the cloth.

There is a force of attraction between the acetate rod and the cloth.

There is a force of repulsion between the acetate rod and the cloth.

Give a reason for your answer.

..........................................................................................................................................

.....................................................................................................................................(2)


(c) Figure 2 shows a Van de Graaff generator, which is used to generate static electricity.

Figure 2

The longer the Van de Graaff generator is switched on, the more charge is stored on the metal dome.

Use an answer from the box to complete the sentence.

decrease increase stay the same

The amount of charge on the metal dome is increased, which causes the potential difference between the metal dome and the earthed sphere to

........................... .(1)

(d) When the potential difference between the Van de Graaff generator and the earthed sphere is 60 kV, a spark jumps between the metal dome and the earthed sphere.

The spark transfers 0.000025 coulombs of charge to the earthed sphere.

The equation which links charge, energy and potential difference is:

energy transferred = charge × potential difference

Calculate the energy transferred by the spark.

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.............................................................................................................................

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Energy transferred = ........................................... J(2)

Score [ /17]


3: Uses and dangers of electrostatic force

Electrostatics CrosswordUse the knowledge you have gained so far in the topic to complete the crossword

Learning Outcomes:

1. Describe the dangers of electrostatic force2. Describe the process of ‘earthing’ and explain why it is important.3. Give two examples of uses of electrostatic force in everyday life and explain

how they work.


The Dangers of Electrostatic Forces

Key Ideas

1. If charges are not earthed they can cause a spark or flash of electricity (e.g. static shocks or lightening).

2. This can be dangerous if you are working with a flammable substance (e.g. refuelling an aeroplane)

3. When a charged object is connected to the Earth, electrons flow between the object and the ground, balancing out the charges.

4. Electrons will flow out of a negatively charged object and in to a positively charged object.

5. Earthing (sometimes referred to as grounding) an object caused the object to become neutral again.


U3: Discharging Pipes Demonstration

In this demonstration your teacher is going to show you the importance of discharging pipes

Draw a diagram of the set up below

Use what you have seen to answer the following questions.

1. An electroscope shows if there is a static charge present. What do you see as the sand is poured down the pipe?

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2. Why is the sand becoming charged?

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3. Workers in oil refineries and chemical works often have to wear special shoes. These shoes have soles which conduct electricity. Why do you think this is?

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4. A heap of flour is difficult to set on fire, but flour dust in the air can explode if ignited by a spark. Why do you think this is?

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Pipe will become chargedduring demonstration. Do not touch until it has been discharged.

Uses of Electrostatics – Comprehension Exercise Read the text below on the formation of stars and use it to answer the questions. To help you focus while reading the text do make use of underlining/highlighting.

For example:

Highlight key words/phrases in yellow Underline words you are unsure of and would like to look up afterwards.

Photocopiers

A selenium-coated aluminium drum is sprayed with positive charge from points on a device called a corotron. Selenium is a substance with an interesting property—it is a photoconductor. That is, selenium is an insulator when in the dark and a conductor when exposed to light.

In the first stage of the process, the conducting aluminium drum is grounded so that a negative charge is induced under the thin layer of uniformly positively charged selenium. In the second stage, the surface of the drum is exposed to the image of whatever is to be copied. Where the image is light, the selenium becomes conducting, and the positive charge is neutralized. In dark areas, the positive charge remains, and so the image has been transferred to the drum.The third stage takes a dry black powder, called toner, and sprays it with a negative charge so that it will be attracted to the positive regions of the drum. Next, a blank piece of paper is given a greater positive charge than on the drum so that it will pull the toner from the drum. Finally, the paper and electrostatically held toner are passed through heated pressure rollers, which melt and permanently adhere the toner within the fibers of the paper.


Inkjet Printers

The ink jet printer, commonly used to print computer-generated text and graphics, also employs electrostatics. A nozzle makes a fine spray of tiny ink droplets, which are then given an electrostatic charge.

Once charged, the droplets can be directed, using pairs of charged plates, with great precision to form letters and images on paper. Ink jet printers can produce color images by using a black jet and three other jets with primary colors, usually cyan, magenta, and yellow, much as a color television produces color.

The nozzle of an ink-jet printer produces small ink droplets, which are sprayed with electrostatic charge. Various computer-driven devices are then used to direct the droplets to the correct positions on a page.

Paint Spraying

Millions of cars are made each year and the steel car bodies must all be painted to prevent them from going rusty. The paint is sprayed onto the car bodies and the process is made more efficient by using electrostatic charge.


The paint spray goes past a high voltage negative needle as it leaves the spray gun and the tiny droplets of paint pick up a negative charge. They do this by gaining negative electrons. It is only the electrons which can move. The car body is then given a high voltage positive charge which attracts the negatively charged paint droplets.

This improves efficiency in two ways.

1. The paint droplets spread out more as they leave the gun. This happens because they all get the same negative charge and so they all repel each other. This is better than coming straight out of the gun as the paint will cover a wider area more evenly.

2. The paint droplets are attracted to the positive metal car body, and so less paint will be wasted by landing on the floor or the walls of the paint shop.

Smoke Precipitators

Another important application of electrostatics is found in air cleaners, both large and small. The electrostatic part of the process places excess (usually positive) charge on smoke, dust, pollen, and other particles in the air and then passes the air through an oppositely charged grid that attracts and retains the charged particles.

Large electrostatic precipitators are used industrially to remove over 99% of the particles from stack gas emissions associated with the burning of coal and oil. Home precipitators, often in conjunction with the home heating and air conditioning system, are very effective in removing polluting particles, irritants, and allergens.

Above is a schematic of an electrostatic precipitator. Air is passed through grids of opposite charge. The first grid charges airborne particles, while the second attracts and collects them.


Questions1. For each of the statements, identify which of the application of electrostatics they

apply to. [More than one may apply] (5)

Statement Photocopier Printer Precipitator

PaintSpraying

Ink particles are charged and their direction determined by two charged plates

Is used to review polluting particles from smoke

Particles (of a substance) are charged

Ink particles are charged and attracted to a surface

Charges (Electrons) are transferred in the process

2. What interesting property of Selenium is useful in photocopiers?

Explain how it works.(2)

………………………………………………………………………………………………………

………………………………………………………………………………………………………

3. How are ink particles directed onto the paper in an inkjet printer? (2)

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4. In paint spraying, how do the ink particles gain a positive charge? (2)

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5. What are electrostatic precipitators very efficient at removing? (1)

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6. How does paint spraying increase its efficiency by charging the paint particles? (2)

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………………………………………………………………………………………………………


7. What is a common use for inkjet printers? (1)

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8. Why must all car bodies be painted? (1)

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9. Where are large electrostatic precipitators commonly used? (1)

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10. Why is the aluminium drum grounded? (1)

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11. How does paint spraying reduce ink waste? (1)

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12. How many filters does a smoke precipitator use? (1)

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13. How does the aluminium drum gain a positive charge? (2)

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14. What occurs in the final stage of photocopying? (2)

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15. Name the particles that are exchanged during charge transfer (1)

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16. Why do ink particles spread out more than usual during paint spraying? (2)

……………………………………………………………………………………………………

……………………………………………………………………………………………………

Score [ /27]


Worksheet: Electrostatics

1(a) On a warm, dry day, you may get an electric shock when you slide out of a car seat and then touch the bodywork of the car.

Explain why this happens.

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(b) If you hold onto the bodywork of the car as you slide out, you do not get a shock.Explain why not.

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(c)Why are you more likely to notice this on a warm, dry day ?

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2(a) Give one way in which static electricity is useful.

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(b)Explain how static electricity is used in photocopying.

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(c) Describe one way in which static electricity is a nuisance (or may be dangerous).

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..............................................................................................................................................................3(a) Static electricity can be used in the spray painting of car bodies.

On the diagram, show the charges on the spray-paint drops and on the car body. [2]

(2)

(b)Carefully explain the process.

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(c)Why should this spray painting be carried out in a dust-free atmosphere ?

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.........................................................................................................................................................(2)

4 (a) An electrical conductor allows the movement of charge. The diagram shows an electrical conductor in the shape of a bar.

On the diagram, draw the pattern of positive and negative charges you would expect to find.[2]

(2)

(b)A positively charged body is brought near to the conductor.

(i) Draw in the new pattern of charges on the conductor. [2]

(2)

(ii) Explain why you have drawn this pattern. [2]

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+

5 (a) A gold-leaf electroscope (shown below) consists of a metal rod, insulated from a case. On the rod is a flat, metal plate. A very thin piece of gold leaf is hinged to the bottom of the rod. The gold leaf is able to move.

When the electroscope is uncharged, there is an even distribution of positive and negative charges on the rod and plate.

A negatively charged rod is brought near the plate.

(i) What would you expect to see ?

..........................................................................................................................................................[1]

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..............................................................................................................................................................(1)

(ii) Explain why you would expect to see this.

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(b)The same thing would happen if a positively charged rod was brought near to the plate.Explain why this would happen.

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metal capmetal rod

insulation plug

metal plate

gold leaf

(c)A rod that has a greater positive charge on it compared to the rod in (b) is brought near to the plate.

What would you see happening this time ?

..........................................................................................................................................................[1]

6. A girl with long, fine hair stands on a rubber mat and puts her hand on the dome of a Van de Graaff generator. The generator is started.

(a)(i) What happens to the girl’s hair ?

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(ii) Explain why this happens.

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(b)(i) What would happen if the girl repeats the experiment, but this time stands on a metal plate ?

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(ii) Explain your answer.

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(c)State two other ways in which the effect on the girl’s hair could be prevented.

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.........................................................................................................................................................(2)

7. The diagram shows a light, conducting sphere, suspended by a cotton thread. It is able to swing freely between the two charged metal plates.

When the sphere is brought into contact with the left-hand plate, it is given a positive charge. The sphere is then allowed to swing freely.

(a)Describe what happens.

..............................................................................................................................................................

..........................................................................................................................................................[2]

(b)Why does the sphere behave like this ?


+

- negatively chargedplate

positively chargedplate

metallisedsphere

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..........................................................................................................................................................[4] Score [ /47]

Stretch Activity – The Gold Leaf Electroscope

Visit the following link:

http://www.absorblearning.com/media/attachment.action?quick=6i&att=460

Using your knowledge of electrostatics, explain what the pictures are showing and hence describe how an electroscope works.

Picture 1 Picture 2 Picture 3

How does an Electroscope work?

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Sketch:

What is happening?

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Sketch:

What is happening?

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Sketch:

What is happening?

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Electrostatics

Past Paper Questions

Q1.


The photograph shows a worker fuelling an aircraft.

Fuelling an electrically-charged aircraft can be dangerous.

The worker connects a safety wire to the aircraft before adding the fuel.

(a) Explain how an aircraft can become electrically charged while it is flying.(2)

............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................

(b) Describe a possible danger of fuelling an electrically-charged aircraft.(1)

............................................................................................................................................ .............................................................................................................................................

(c) What electrical connection is made by the safety wire?(1)

.............................................................................................................................................

(d) Explain how connecting the safety wire reduces the possible dangers when fuellingan electrically-charged aircraft.

(2) ............................................................................................................................................. .............................................................................................................................................


............................................................................................................................................. .............................................................................................................................................

(Total for question = 6 marks)


Q2.

This question is about static electricity.

(a) Which of these materials is an electrical conductor?(1)

A paper

B plastic

C silver

D wood

(b) A forensic scientist uses an electrostatic dust print lifter (EDPL) to take impressions offootprints.

The diagram shows a simplified EDPL and a description of how it works.

Use the idea of charge movement to explain how the lifting sheet becomesnegatively charged and the metal plate becomes positively charged.

(2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................


. .............................................................................................................................................

(c) The photograph shows a typical dust print on a lifting sheet.

Suggest why dust particles are lifted off the floor on to the lifting sheet.(2)

............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................

(d) This photograph shows a charged polythene rod placed next to a stream of waterflowing from a tap.

Suggest why the water is deflected.


(2) ............................................................................................................................................ ............................................................................................................................................. ............................................................................................................................................ .............................................................................................................................................



Q3.

In 1901, Marconi received the first radio signal across the Atlantic Ocean.

The signal was the letter S in Morse code (three 'dots') sent over and over again.

Each letter S was produced by quickly turning an electric spark on and off three times.

The graph shows how the strength of the signal changed with time.

(a) The frequency of Marconi's radio wave was 820 kHz and the wavelength was 366 m.(i) State the equation linking wave speed, frequency and wavelength for radio waves.

(1)

(ii) Calculate the speed of the radio waves Marconi received.(2)

Speed of radio waves = ........................................................... m/s


(c) Some people do not believe that Marconi received 820 kHz radio waves.They think that the frequency was really twice as much: 1640 kHz.If these people are correct, what wavelength radio waves did Marconi receive?

(1)

Wavelength = ........................................................... m

(d) Other people do not think Marconi received a radio signal across the Atlantic Ocean at all.

They think the radio waves he received were really caused by electrostatic dischargesfrom storm clouds.

Explain what happens when a storm cloud discharges.(3)

............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................. ............................................................................................................................................


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Q4.

This question is about electrostatic charges.

(a) Complete the sentences using words from the box.Each word may be used once, more than once or not at all.

(2)

When a plastic rod is rubbed with a cloth, the plastic rod gains ..............................................................After the plastic rod has been rubbed with the cloth, the plastic rod has a.............................................................. charge.

(b) Electrostatic charges can be useful during paint spraying.

(i) The droplets of paint are given the same charge as they leave the sprayer.

Explain why this is an advantage.

(2)

.............................................................................................................................................

.............................................................................................................................................

.............................................................................................................................................

.............................................................................................................................................


(ii) The droplets of paint are positively charged.

The object being painted is given a negative charge.

Explain why this is an advantage.

(2)

.............................................................................................................................................

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(c) Give one hazard caused by electrostatic charges and state how the risk from this

hazard can be reduced.

(2)

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Electrostatics

Spec Point Notes


Electrostatics Specification Notes

2.01 use the following units: ampere (A), coulomb (C), joule (J), ohm (Ω), second (s),

2.22 identify common materials which are electrical conductors or insulators,

including metals and plastics

Good Conductors Good Insulators

Graphite

Metals

o Gold

o Copper

o Tin

Plastic

Rubber

Glass

Wood

2.23 practical: investigate how insulating materials can be charged by friction

See pages 6 and 7 for this practical.

2.24 explain how positive and negative electrostatic charges are produced on

materials by the loss and gain of electrons

2.25 know that there are forces of attraction between unlike charges and forces

of repulsion between like charges


https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwir0e-P5LDdAhUBz4UKHQuqAlAQjRx6BAgBEAU&url=https://learn.sparkfun.com/tutorials/what-is-electricity/flowing-charges&psig=AOvVaw065ivTOKv2nNfn-EMj3tnN&ust=1536680763871921

2.26 explain electrostatic phenomena in terms of the movement of electrons

2.27 explain the potential dangers of electrostatic charges, e.g. when fuelling

aircraft and tankers

2.28 explain some uses of electrostatic charges, e.g. in photocopiers and inkjet

Printers

Please refer to pages 89-91 of your Textbook for detailed explanations.


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