# Plasma & the elemental table

Where can I find a list/chart of the temperatures at which elements reach the 4th state of matter known as plasma?

## Answers and Replies

So I believe that it will not be as simple as finding a table with elements and temperatures but it is possible that you could make sure a table with some assumptions.

First off, do you know what a plasma is? In short a gas becomes a plasma when electron(s) are removed from the nucleus. The process of removing an electron from an atom is called ionization. Consider removing the electrons off of an atom one by one. After you remove the first electron, I would say the atom has been singly ionized. After two electrons are pulled off it would be doubly ionized and so on until all of the electrons are removed which I would call fully ionized.

Now when you as for the temperatures at which elements become plasmas, I would rephase it as, at what temperature would a singly ionized plasma of element X be in thermal equilibrium? Now a further complication is that in thermal equilibrium the plasma might be made up of ions with different levels of ionization but let's not get into that.

So we need to know at what energy are the elements singly ionized. Then the temperature that corresponds to that first ionization energy is roughly what you are looking for.

$T = E / K_b$

where T is temperature, E is energy, and $K_b$ is the Boltzmann constant.

I think the following site provides the ionization (binding) energies for many elements (the energy in eV at the bottom of a given column is what is needed for singly ionized atom).

http://www.chembio.uoguelph.ca/educmat/atomdata/bindener/elecbind.htm

The following Wolfram Alpha link is an example for Hydrogen