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Calculate the number of states per cubic...

Calculate the number of states per cubic metre of sodium in 3s band. The density of sodium is `1013kgm^(-3)`.How naby of them are empty?

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`f = 1018 kg/m^(2),V = 1m`
`m = fV = 1013 xx 1 = 1013 kg`
Number of atome
` = (1013 xx 10^(-3) xx 6 xx 10^ (23))/(23)`
`((1013 xx 6)/(23)) xx 10^(26)`
` = 364.26 xx 10^26`
`(a)Total number of ststes
`N = 2 xx 264.26 xx 10^(26)`
` = 528.5210^(26) = 5.3 xx 10^(28)`
(b)Total number of unoccupied states
` = 2.65 xx 10^(28)`
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  16. In a p-n junction, the depletion region is 400nm wide and and electric...

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