Chemical bonds, ionic, covalent and metallic key terms

dot and cross diagram

A diagram that represents the transfer of electrons between atoms in ionic bonding.

electron transfer

The process by which electrons move from one atom to another during ionic bonding.

ionic compound

In Ionic compounds, ionic compound means a giant structure formed from a lattice of oppositely charged ions. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to describe an ionic compound as a giant structure of oppositely charged ions. Use ionic compound only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

ionic lattice

A three-dimensional structure where strong electrostatic attractions act in all directions between oppositely charged ions.

electrostatic attraction

The force that attracts oppositely charged ions towards each other in an ionic lattice.

ionic lattice

A three-dimensional structure formed by a regular arrangement of oppositely charged ions.

ionic compound

A giant structure of oppositely charged ions held together by strong electrostatic attractions.

ionic structure

A representation that shows the arrangement of ions in an ionic compound, often depicted using diagrams.

dot and cross diagram

A visual representation showing the transfer of electrons between atoms in ionic compounds.

giant ionic structure

A large lattice arrangement of oppositely charged ions held together by strong electrostatic attractions.

ball and stick diagram

A model used to represent the arrangement of atoms in a molecule, showing bonds as sticks and atoms as balls.

giant ionic structure

A large lattice arrangement of oppositely charged ions held together by strong electrostatic forces.

two-dimensional diagram

A flat representation that shows the arrangement of ions in a giant ionic structure but lacks depth.

three-dimensional diagram

A representation that illustrates the spatial arrangement of ions in a giant ionic structure, providing a more accurate depiction than two-dimensional diagrams.

ionic compound

In Ionic compounds, ionic compound means a giant structure formed from oppositely charged ions. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to work out the empirical formula of an ionic compound from a model or diagram of its ions. Use ionic compound only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

empirical formula

In Ionic compounds, empirical formula means the simplest whole number ratio of atoms in a compound. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to work out the empirical formula of an ionic compound from a model or diagram of its ions. Use empirical formula only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

sodium chloride

In Ionic compounds, sodium chloride means a common example of a giant ionic lattice formed from sodium and chloride ions. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to use sodium chloride as the familiar example of a giant ionic lattice without needing other specific ionic structures. Use sodium chloride only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

giant ionic lattice

A three-dimensional structure of oppositely charged ions held together by strong electrostatic forces.

covalent bond

In Covalent bonding, covalent bond means a bond formed when atoms share pairs of electrons. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to describe covalent bonding as atoms sharing pairs of electrons. Use covalent bond only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

shared electron pairs

In Covalent bonding, shared electron pairs means electrons that are shared between two atoms to form a covalent bond. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to describe covalent bonding as atoms sharing pairs of electrons. Use shared electron pairs only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

covalent bond

In Covalent bonding, covalent bond means a strong attraction between atoms that share pairs of electrons. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to explain that covalent bonds between atoms are strong. Use covalent bond only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

strong attraction

In Covalent bonding, strong attraction means the chemistry idea used to explain that covalent bonds between atoms are strong. Use this term specifically in Chemical bonds, ionic, covalent and metallic when explaining this objective, so it is not confused with a broader bonding, structure, or materials term.

small molecule

In Covalent bonding, small molecule means a molecule that consists of a small number of atoms covalently bonded together. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to recognise common small molecules from their chemical formulae. Use small molecule only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

chemical formula

A representation of a substance using symbols for its constituent elements and numbers to indicate the ratio of atoms.

polymer

A large molecule formed by the repeated linking of smaller units called monomers through covalent bonds.

covalent substance

In Covalent bonding, covalent substance means a material composed of molecules formed by atoms sharing pairs of electrons. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to recognise that some covalent substances form very large molecules such as polymers. Use covalent substance only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

giant covalent structure

A large network of atoms bonded together by covalent bonds, such as diamond or silicon dioxide.

covalent bond

In Covalent bonding, covalent bond means a strong attraction between atoms that share pairs of electrons. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to recognise that some covalent substances form giant covalent structures such as diamond and silicon dioxide. Use covalent bond only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

dot and cross diagram

A visual representation showing the sharing of electron pairs between atoms in covalent bonding.

covalent bond

In Covalent bonding, covalent bond means a chemical bond formed when two atoms share pairs of electrons. This matters in Chemical bonds, ionic, covalent and metallic because it supports the learning objective to draw dot and cross diagrams for hydrogen, chlorine, oxygen, nitrogen, hydrogen chloride, water, ammonia and methane. Use covalent bond only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.