
Atom
Chemical Composition
Atoms bond together to form molecules, which make up matter.
Water is composed of hydrogen and oxygen atoms.
Indivisible Concept
Historically, atoms were thought to be indivisible; now we know they consist of smaller particles.
Atoms are made up of protons, neutrons, and electrons.
Unique Identity
Every element on the periodic table is defined by the number of protons in its atoms.
Carbon atoms have six protons each.