Chemistry definitions Atomic structure 1. Atomic number: number of protons in the nucleus of an atom. 2. Mass number: protons and neutrons in a nucleus of an atom. 3. Isotopes: are atoms of the same element have in the same number of protons but different numbers of neutrons. 4. Relative atomic mass: the average mass of naturally occurring atoms of an element on a scale where a carbon 12 atom has a mass of exactly 12 units Types of bonding 1. Ion: a charged particle by losing or gaining electrons. 2. Ionic bond: transfer of electrons from a metal to a nonmetal forming positive and negative charged ions. 3. Valency: electrons lost or gained to reach full outer shell. 4. Giant ionic structure: regular arrangement of alternating opposite charged -ve and +ve ions. 5. Covalent bonds: sharing of electrons between nonmetals. 6. Molecules atoms held up by covalent bonds 7. Allotropes different structures of the same element 8. Macromolecules: billions of atoms held up by covalent bonds. 9. Element: simplest form of a pure substance consists of only one type of atoms and can’t be broken into anything simpler. 10. Metallic lattice: regularly arranged players of positive ions embedded in a sea of delocalized electrons. 11. The metallic bond: is the force of attraction between layers of metals positive ions and the electron sea they’re embedded in. 12. Compound: Two or more atoms chemically bonded together. Redox 1. Redox: reduction and oxidation occur side by side at the same time during a chemical reaction 2. Reduction: loss of oxygen 3. Oxidation: gain of oxygen 4. An oxidizing agent: a substance that oxidizes something and being its self-reduced 5. A reducing agent: a substance that reduces something and being itself oxidized 6.