Metal | \[Li\] | \[Na\] | \[K\] | \[Mg\] |
\[\phi (\,eV)\] | \[2.4\] | \[2.3\] | \[2.2\] | \[3.7\] |
A) \[Li.Na\]
B) \[Na,K\]
C) \[Li,\,\,K\]
D) \[K,\text{ }Mg\]
Correct Answer: B
Solution :
[b] Since the value of \[hc=1240\text{ }eV\text{ }nm.\] Energy corresponding to \[\lambda =500\text{ }nm\]is: \[\frac{1240\,eV\,nm}{520\,nm}=2.38\,eV\] Element having \[\phi <2.38\,eV\]will show photoelectric effect, are \[Na(2.3)\] and \[K(2.2)\] Hence option is (2)You need to login to perform this action.
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