# Ionization and light

1. Jul 2, 2006

### z-component

[SOLVED] Ionization and light

I've been working on this problem and I'm not coming up with a reasonable answer.

If the Bohr model is used, what frequency of light
would be required for ionization of hydrogen?

I know that $$\Delta E = h \nu$$, where E is energy, h is Planck's constant, and $\nu$ is frequency and that $$\nu = \frac{c}{\lambda}$$ and I know the first ionization energy of hydrogen is 1312 kJ/mol, but I can't seem to arrive at the answer.

I tried using both 1312kJ and 1.312x10^6J for E but the answer comes out too large. The solution is 3.29 × 10^15 Hz. Any help is appreciated.

2. Jul 2, 2006

### Renge Ishyo

First step: Questions like this should be on the homework forum, so you probably might want to post there next time.

Next step: Divide the ionization energy (in J) per mol by 6.023x10^23 to get the ionization energy per electron. You should get a number like 2.1783x10^-18 J which should look somewhat familiar to you. This is your E.

Next Next step:

2.7183X10^-18 J = (6.63x10^-34 J*s)f

f = 3.29x10^15 Hz

3. Jul 2, 2006

### z-component

Yep, this is actually my first homework question and I forgot about that forum, actually. Thanks for your response!