Ligações Metálicas Bond between atoms with similar low electronegativities (ΔX ~0). Metallic...
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Ligações Metálicas Bond between atoms with similar low electronegativities (ΔX ~0). Metallic bonding is essentially covalent bonding with delocalized electrons. Metallic nuclei sharre weakly bonded valence electrons, which form an "electron gas". Metals have many more empty orbits than electrons available to fill them. For example, Fe requires 5 electrons to fill its outermost 3d shell. Metallically bonded solids share the following properties: low to moderate hardness, malleability and ductility (weak delocalized bonds); very good thermal and electrical conductivity (free electrons in
Transcript of Ligações Metálicas Bond between atoms with similar low electronegativities (ΔX ~0). Metallic...
Ligações Metálicas
Bond between atoms with similar low electronegativities (ΔX ~0). Metallic bonding is essentially covalent bonding with delocalized electrons. Metallic nuclei sharre weakly bonded valence electrons, which form an "electron gas". Metals have many more empty orbits than electrons available to fill them. For example, Fe requires 5 electrons to fill its outermost 3d shell. Metallically bonded solids share the following properties: low to moderate hardness, malleability and ductility (weak delocalized bonds); very good thermal and electrical conductivity (free electrons in cloud); and form crystals with high symmetry (nuclei pack well).
Efeito de um Campo
Corrente
dQI
dt
Corrente, velocidade de arraste e densidade de corrente.
dAv dt volume percorridoparticulas
nVolume
ddQ qnAv dt
d
dQI qnAv
dt d
IJ qnv
A
Vetor densidade de CorrenteCorrente não tem sinal, repare que se a carga mudar de sentido, a velocidade também mudará. Mas, há o vetor densidade de corrente:
dJ nqv
Sempre apresenta o sentido do campo elétrico.
Resistividade
Em um material ôhmico:
E
J
Para um metal:
0 0(T) 1 T T
Resistência
E J
V E dL EL r r
A
I JdA JA L
V IA
Resistência
V RI
LR
A
0 0R(T) R 1 (T T )
Força Eletromotriz e Circuitos
abV IR
abV
Força Eletromotriz e Circuitos
abV Ir
Ir R
0 Ir IR
Energia e Potência
ab abdW V dQ V Idt
ab
dWP V I
dt
Para um resistor:
ab
22
ab
VV IR P I R
R
Esta é a energia dissipada no resistor.
Bateria
2produzidaP I I r
2gastaparacarregarP I I r
Alternador
Exercícios
26.43,26.44, 26.47, 26.48, 26.50, 26.52,26.61,26.62,26.64
![A topological analysis of the bonding in [M2(CO)10] and [M3 ......function (SF) · Transition metal carbonyl complexes · Multicenter bonding 1 Introduction In the last two decades,](https://static.fdocument.org/doc/165x107/61284c34ccc7f66b051135f1/a-topological-analysis-of-the-bonding-in-m2co10-and-m3-function-sf.jpg)
