Atoms

Simple, pure, substance which cannot be devided into simpler substances by chemical means

smallest part of any element, that can take part in a chemical reaction

Smallest part of an element or compound which can exist independently (H2)

Atoms from two or more elements combone chemically

Two or more substances migled each other but not joined together chemically

Atoms having the same no of protons but different numbers of neutrons

More neutrons = greater mass

Number of protons in an atom, in its normal state

Average mass of an atom

Neutrons + Protons