Question

What wavelength, in nm, can strike a metal surface and eject an electron at 1.89 × 10–19 J if the binding energy of the metal is 289 kJ/mol?

Answer 1

The wavelength that can eject electron at given energy is 1052 nm.

The wavelength can be calculated by the formula - hc/E.

H debtors Plank's constant.

Value of h is 6.626 * 10^-34 Js.

C is speed of light.

Value of c is 3*10^8 m/s.

E is given in the question i.e. 1.89*10^-19 J.

Thus, putting the values in formula, the wavelength will be 1.052 * 10^-6 m.

Since 1m = 10^9 nm.

Thus, wavelength required will be 1052 nm.