Question

Assuming an ionization efficiency of 13.0%, how many such photons are needed to ionize 1.00×1016 atoms?

Answer 1

Answer:

7.69x$10^{16}$

Explanation:

The ionization is the energy necessary to transform an atom in an anion. So, it's the energy it requires to gain an electron.

This ionization occurs for the photoelectric effect - the emission of electrons by  metal using photons. So, if the efficiency is 100%, 1 photon can ionize 1 atom, but for an effficiency of 13.0%:

N = $\frac{1.00x10^{16}}{0.13}$

N = 7.69x$10^{16}$

Where N is the number of photons.