Question

The first ionization energy of bismuth is ei1 = +703 kj/mol. what is the longest possible wavelength of light that could ionize an atom of bismuth?

Answer 1

Hey there!:

Given, energy, E = 703 kJ/mol

λ = ?

We need to do conversion of kJ/mol to J

So, E = 703 kJ/mol*1000 J*kJ *1 mole / 6.023*10²³

 = 1.17*10-18 J

We know formula,

E = h*C/ λ

So, λ = h*C / E

=  ( 6.626*10-34 J.s ) *  ( 3.0*10⁸ m.s⁻¹ ) /  ( 1.17*10⁻¹⁸ J )

= 1.70*10⁻⁷ m

So, 1 m = 1*10⁹ nm

So, 1.70*10⁻⁷ m = ?

= 170 nm

Hope that helps!