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The density of copper is 9xx10^3 kg m^(-...

The density of copper is `9xx10^3 kg m^(-3)` and its atomic mass is 63.5 u. Each copper atom provides one free electron. Estimate the number of free electrons per cubic metre in copper.

A

`10^(19)`

B

`10^(23)`

C

`10^(25)`

D

`10^(29)`

Text Solution

Verified by Experts

The correct Answer is:
D
`rho_(Cu) = 9 xx 10^(3) kg//m^(3), m_(Cu^(-)) = 63.5 g`
No. of electron per unit volume
`=N_(A)/M rho =(6.02 xx 10^(23))/(63.5 xx 10^(-3)) xx 9 xx 10^(3)`
`=0.85 xx 10^(29)//m^(3)`
Approx = `10^(29)//m^(3)`
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