Definitions (CHEMISTRY)

Proton(atomic) number

The number of protons present in the nucleus of an atom

Nucleon(mass) number

The total number of protons and neutrons present in the nucleus of an atom

Isostopes

Isotopes are elements with the same number of protons but different number of neutrons

Ionic bond

Ionic bond is the strong electrostatic forces of attraction between positively charged ions and negatively charged ions

Covalent bond

Covalent bond is the electrostatic forces of attraction between the sharing of electrons and the two positively charged nuclei

Metallic bond

Metallic bond is the strong electrostatic forces of attraction between positive metal ions and ‘sea of delocalised electrons’

Elements

An element is a pure substance that is only made up of one type atom and cannot be broken down into simpler substances by chemical preocesses

Compound

A compound is a pure substance that is made up of two or more elements chemically combined together

Mixtures

A mixture consists of two or more substances that are not chemically combined together

Relative Atomic Mass

Relative atomic mass is the average mass of one of one atom of an element compared to 1/12 of the mass of a carbon-12 atom

Relative Molecular Mass

Relative molecular mass is the average mass of one molecule/one formula unit of a substance compared to 1/12 of the mass of a carbon-12 atom

Mole

Mole is defined as the amount of substance that consists the same number of particles as the number of atoms in 12g of carbon-12

Acids

Acids are substances the release hydrogen ions when dissolved in water

Alkalis

Alkalis are substances that release hydroxide ions when dissolved in water

Salt

Salt is a substance formed when hydrogen ions in acids are replaced by metal or ammonium ions