The first ionization energy is the amount of energy required to remove the outermost electron from an atom in its gaseous state.
First Ionization Energy cheat sheet for homework
The distance from the center of an atom's nucleus to its outermost electron.
A measure of an atom's ability to attract electrons towards itself in a chemical bond.
Shielding Effect: The reduction in attraction between an electron and the nucleus due to the presence of other electrons.