The wave function of a metal is 8.0 x (10^{-19})J. Calculate the wavelength of its threshold frequency. (Speed of light in a vacuum = 3 x (10^8ms^{-1}, Planck’s constant = 6.6 times 10^{-34})Js)
-
A.
0.8 x (10^{-7})m -
B.
1 x (10^{-7})m -
C.
2.3 x (10^{-7})m -
D.
3.8 x (10^{-7})m -
E.
12.4 x (10^{-7})m
Correct Answer: Option C
Explanation
(theta = E – E_f = h_f = frac{v}{lambda} Rightarrow = lambda = frac{h_v}{theta}
frac{6.6times 10^{-34} times 3 times 10^{8}}{8.6 times 10^{-19}} = 0.8 times 10^{-7})m