0653 Chemistry (2025-2027) Syllabus : Define and Describe

1. 0653 Definitions

• 1. Activation energy, Ea

• 1. Total number of protons and neutrons in the nucleus of an atom.

• 1. Proton number/atomic number

• 1. The minimum energy that colliding particles must have to react.

• 1. Mass number/nucleon number

• 1. A family of similar compounds with similar chemical properties.

• 1. Homologous series

• 1. Large molecules built up from many smaller molecules called monomers.

• 1. Polymers

• 1. Number of protons in the nucleus of an atom

0653 Definitions 2

• 1. Reduction

• 1. Loss of oxygen.

• 1. Oxidation

• 1. A reaction involving simultaneous oxidation and reduction.

• 1. Redox reaction

• 1. The decomposition of an ionic compound, when molten or in aqueous solution, by the passage of an electric current.

• 1. Electrolysis

• 1. Gain of oxygen.

0653 Chemistry Definitions 3

• 1. Ionic bond

• 1. The number and type of atoms in one molecule.

• 1. Molecular formula

• 1. Molecules in which one or more carbon–carbon bonds are not single bonds.

• 1. Unsaturated compound

• 1. A bond formed when a pair of electrons is shared between two atoms.

• 1. Covalent bond

• 1. Compounds that contain carbon and hydrogen only.

• 1. Hydrocarbon

• 1. Strong electrostatic attraction between oppositely charged ions.

• Describe the structure of the atom as a central nucleus containing _____________ and protons, surrounded by electrons in shells 

• Positive ions are known as ____________.

Negative ions are known as__________.

• Describe the______________________ structure of ionic compounds as a regular arrangement of alternating positive and negative ions

In electrolysis, the positive electrode is the __________.

In electrolysis, the negative electrode is the _____

In electrolysis, the ___________ is a molten or aqueous substance that is separated.