Chapter 5 Chemical Bonding and Sturcture

Key terms to memorise

Compound

Substance made up of two or more different elements combined together chemically

Octet Rule

When bonding occurs, atoms tend to reach electron arrangement with 8 electrons in outermost energy level

Ion

Charged atom/group of atoms

Ionic bond

Force of attraction between oppositely charged ions in compound. Bonds are always formed by complete transfer of electrons from one atom to another

Cation

Positive ion

Anion

Negative ion

Transition metal

One that forms at least one ion with a partially filled d sublevel

Transition metal properties

Variable valency, usually forms coloured compounds, widely used as catalysts

Covalent bond

Chemical bond formed when two atoms share pair(s) of electrons

Molecule

Group of atoms joined together. Smallest particle of an element/compound that can exist independently

Valency

The number of atoms of hydrogen or any other monovalent element with which each atom of the element combines.

Sigma bond

Head-on overlap of two orbitals

pi bond

sideways overlap of p orbitals

VSEPR Theory Full Name

Valence Shell Electron Pair Repulsion Theory

VESPR Theory explanation

States that the shape of a molecule depends on the number of pairs of electrons around the central atom. Since electrons are negatively charged, electron pairs repel each other and arrange themselves in space so that they are as far apart as possible

Precipitation reaction

Reaction in which an insoluble substance is produced from soluble substances in solution.

Precipitate

The insoluble substance formed in a precipitation reaction