A molecule is a particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together.

When an atom has a full outer shell of electrons, it has a noble gas electron configuration.

The outer shell is the highest energy level in an atom and is usually the furthest from the nucleus.

Why chemical reactions occur

Chemistry

In the Chemistry of Carbon unit, pupils will build on their understanding of chemical bonding to explore the unique properties and bonding of carbon, leading to various natural and synthetic organic compounds.

In the Atomic Structure and the Periodic Table unit, pupils learned about the model of the atom, isotopes, and the arrangement of elements in the periodic table.

Structure and bonding

A malleable substance can be hammered or pressed into shape without breaking.

A ductile substance has the ability to be drawn into a wire.

Electrons are said to be delocalised when they are free to move through the structure of a metal and can carry an electrical current.

A conductor is a substance that allows charge or energy to flow through it easily due to the presence of delocalised electrons.

A force of attraction refers to the strength of the pull between two objects either due to their mass, their charge or the presence of magnetic poles.

Metallic structure and properties

An alloy is a mixture of two or more elements, where at least one element is a metal.

A physical property is a characteristic of a substance that can be observed or measured. For example, the temperature at which a substance melts.

Molten is the term used to describe a liquid substance formed by heating solid metals, glass, or rocks.

Metal alloys

A mixture of two or more elements, where at least one element is a metal.

An alloy of iron that contains specific amounts of carbon and may contain other metals.

A substance that has the ability to break up easily.

Alloys and their properties

An atom or molecule that has lost or gained one or more electrons so has a charge.

Used to show how chemical bonds are formed between atoms – the electrons from one atom are shown as dots and the electrons from the other atom are shown as crosses.

Forming ions for ionic bonding (RAM 1 d.p.)

the electrostatic force of attraction between oppositely-charged ions acting in all directions

used to represent the atoms and bonds in a chemical compound

the regular arrangement of atoms or ions in a 3D space

Giant ionic structures

The simplest whole number ratio of atoms of each element in a compound.

Ions that are made up of more than one type of atom.

The name ending for a compound with a metal and non–metal present, for example, potassium iodide (KI).

The name ending for a compound with three or more elements present (one of which is oxygen), for example, potassium sulfate (K₂SO₄).

Determining ionic formulae

is made up of two different elements, one of which is a metal and the other a non-metal element.

show the simplest whole number ratio of atoms of each element in a compound.

can be used to determine the size of one quantity in relation to another.

is used to show how chemical bonds are formed between atoms. The electrons from one atom are shown as dots and the electrons from the other atom are shown as crosses.

is the size of a quantity, for example the size of the charge on the ion.

Ionic diagrams for binary ionic substances

The temperature at which a substance changes from solid state to a liquid state.

A particle that enables electrical conductivity, such as delocalised electrons or free–moving ions.

When a substance's particles separate and spread throughout the particles of a solvent resulting in it no longer being seen.

The ability of a substance to dissolve in a particular solvent creating a solution; how well a solute dissolves in a solvent.

Properties of giant ionic structures

A particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together.

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Is used to show how chemical bonds are formed between atoms. The electrons from one atom are shown as dots and the electrons from the other atom are shown as crosses.

Shows the simplest whole number ratio of atoms of each element in a compound.

A 2D model of a covalent substance, showing all its atoms and bonds. Lines are used to represent shared pairs of electrons.

Forming covalent bonds

a particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together

the strong electrostatic force of attraction between  a shared pair of electrons and the nuclei of bonded atoms

the weak forces of attraction between molecules and molecular substances

a substance that has a large regular arrangement of atoms all joined together by covalent bonds

a long chain molecule formed by joining small molecules (monomers) together by covalent bonds

Properties of covalent substances

used by scientists to represent parts of the natural world that are too difficult to observe or explain directly

used to show how chemical bonds are formed between atoms

a 3D molecular model where the atoms are represented by spheres

a 2D model of a covalent substance, showing all its atoms and bonds

Structure and bonding

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These lessons will be removed by end of Summer Term 2025.