Inch

A unit of length equal to 1/12 of a foot or 2.54 centimeters

Integer

This is the name for numbers such as 0, 1, 2 that are whole numbers without fractions.

Insulator

Materials that DO NOT allow electrons to move freely between atoms and molecules (e.g. plastic).

Ion

Ions are atoms with an electric charge. If they have more protons than electrons, they will have a positive charge, and if they have more electrons than protons, they will have a negative charge.

Isotope

Atoms with the same number of protons but different numbers of neutrons. click to enlarge.