List of definitions

Chemistry : the study of matter and changes it undergoes

Elements : substance that cannot be seperated into simple substance by chemical means.

Compounds : substance that composed of atoms of two or more elements chemically

united in fixed proportion.

Molecule : aggregate of two or more atoms in definite arrangement held by chemical

forces(covalent bond)

Polyatomic ions : group of atoms that have overall changes

Atom : smallest particle inside element, but still identified by that element

Isotope : atoms that have the same no of proton but different number of neutron.

Molecular equation: shows the complete formula of every substance

Ionic equation : show the ions that make up the substance

Relative isotopic mass : mass of an atom of an isotope relative to mass of C-12

Relative atomic mass : average mass of an element’s isotope relative to mass of C-12

Relative molecular mass : sum of relative atomic mass of all the atoms in molecular

compound.