Imperial System - An older way of measuring things like length, weight, and volume, using units like inches, feet, pounds, and gallons. Used in the USA and it's called "Imperial" because it was developed during the time of the British Empire.
Inert – elements and/or compounds that when put together are unable to react chemically.
Inertia - a property of matter by which it remains at rest or in unchanging motion unless acted on by some external force
Inorganic Compound - compounds that do not contain both carbon and hydrogen
International System of Units (SI) - the global standard for measuring things, like how tall something is (in meters) or how much it weighs (in kilograms)
Ion – an atom that has gained or lost one or more electrons.
Ionic Bond – a bond formed by the transfer of electrons (when valence electrons of one atom are transferred to the outer energy level of another atom).
Ionization - A physical change in which a substance changes from a gas to the plasma state due to extremely high temperatures. It can also be a process in which atoms gain or lose electrons.
Isobars - Lines on a weather map connecting points of equal atmospheric pressure. Isobars are used to depict pressure patterns and identify areas of high and low pressure.