Atom
The smallest particle of a chemical element that can exist. The building block of matter (which makes up everything).

Matter
The substance or substances of which any physical object consists or is composed.

Atomic Particle
A particle of which an atom is made of.. Either a proton, neutron or electron.

Electron

Neutron

Proton

AMU
An atomic mass unit (a unit of measurement of atoms). Calculated by the mass of the protons and neutrons (electrons aren’t counted in simple calculations because it weighs 1/1840 AMU)

Electron Shell
An electron shell is the outside part of an atom around the nucleus. Electrons are contained in the electron shell.

Element
An element is a substance which is comprised of the same type of atom (all of the atoms have the same number of protons).

Compound
A compound is a substance where two or more types of atoms (or the same type of atom) are bonded together. (In mixtures the atoms are not chemically bonded).

Periodic Table

Atomic Number
The number of protons in the nucleus of an atom of a particular element and also determines the elements place in the periodic table.

Atomic Mass
The mass of an atom of a certain element. Often calculated by adding the mass of the protons and neutrons in the atom.

Alchemists
A person who transforms or creates something through a seemingly magical process. They were popular during the medieval times.

Investigations
A formal inquiry or systematic study.
Observations
A statement based on something one has seen, heard or noticed.
Scientists
A person who is studying or has expert knowledge of one or more of the natural or physical sciences.

Chemical Symbol
For example - He = Helium
For example - Fe = Iron (Ferrum is the Latin name for iron)

Anions
Negatively charged atoms with a full valence shell that are formed when atoms gain electrons to make a full valence shell.
Cations
Positively charged atoms with a full valence shell that are formed when atoms lose electrons to make a full valence shell.
Metals
Metalloids
Non-Metals
Valence Electrons