How bonding and structure are related to the properties of substances key terms

intermolecular forces

Forces that occur between molecules, affecting properties such as melting and boiling points.

polymer

A very large molecule made from atoms linked by covalent bonds, often exhibiting unique properties.

polymer

In Polymers, polymer means a very large molecule made from atoms linked by covalent bonds. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to explain why many polymers are solids at room temperature. Use polymer 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.

room temperature

the typical temperature range of 20-25 degrees Celsius at which many polymers exist as solids.

giant covalent structure

In Giant covalent structures, giant covalent structure means a structure where atoms are linked by many strong covalent bonds. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to describe giant covalent substances as structures where atoms are linked by many strong covalent bonds. Use giant covalent structure 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 covalent bond

A bond formed when atoms share electron pairs, resulting in a strong connection between them.

giant covalent structure

A structure where atoms are linked by many strong covalent bonds, resulting in high melting points.

high melting point

The temperature at which a solid becomes a liquid, often associated with strong forces between particles.

covalent bond

In Giant covalent structures, covalent bond means a strong bond formed when two atoms share electron pairs. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to explain that covalent bonds must be overcome to melt or boil a giant covalent substance. 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.

giant covalent substance

A structure where atoms are linked by many strong covalent bonds, resulting in high melting and boiling points.

diamond

In Giant covalent structures, diamond means a giant covalent structure where each carbon atom forms four strong covalent bonds. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to identify diamond, graphite and silicon dioxide as examples of giant covalent structures. Use diamond 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.

graphite

A giant covalent structure where each carbon atom forms three covalent bonds, allowing layers to slide over each other.

giant covalent structure

In Giant covalent structures, giant covalent structure means a structure where atoms are linked by many strong covalent bonds. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to recognise giant covalent structures from diagrams showing bonding and structure. Use giant covalent structure 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.

bonding diagram

A visual representation showing how atoms are connected in a giant covalent structure.

metallic bonding

The attraction between positive metal ions and delocalised electrons, responsible for the properties of metals.

high melting point

The temperature at which a solid metal becomes a liquid, typically due to strong metallic bonding.

pure metal

In Properties of metals and alloys, pure metal means a metal that consists of atoms arranged in regular layers. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to describe pure metals as atoms arranged in regular layers. Use pure metal 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.

regular layers

The structured arrangement of atoms in pure metals that allows them to slide over each other.

layers of atoms

In Properties of metals and alloys, layers of atoms means arrangements of atoms in pure metals that allow them to slide over each other. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to explain why layers of atoms in pure metals can slide, allowing metals to be bent and shaped. Use layers of atoms 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.

bending and shaping

The ability of metals to be deformed without breaking due to the sliding of atom layers.

pure metal

In Properties of metals and alloys, pure metal means a metal that consists of only one type of atom arranged in regular layers. This matters in How bonding and structure are related to the properties of substances because it supports the learning objective to explain why pure metals may be too soft for some uses. Use pure metal 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.

softness

The property of a material that allows it to be easily deformed or shaped, often due to the arrangement of its atoms.

alloy

A mixture of two or more elements, where at least one is a metal, that has enhanced properties compared to the individual metals.

distortion of atom layers

The alteration of the regular arrangement of atoms in a metal due to the presence of differently sized atoms in an alloy, making it harder.

delocalised electron

An electron that is not associated with a single atom or bond and can move freely within a metallic structure, allowing for electrical conductivity.

charge carrier

A particle, such as a delocalised electron, that carries an electric charge and enables the conduction of electricity in materials.

delocalised electron

An electron that is not associated with a specific atom and can move freely within a metallic structure, allowing for the conduction of electricity and thermal energy.

thermal conductivity

The ability of a material to conduct thermal energy, which in metals is facilitated by the movement of delocalised electrons.

metallic conductivity

the ability of metals to conduct electricity due to the movement of delocalised electrons.

ionic conductivity

the ability of ionic compounds to conduct electricity when molten or dissolved, due to the movement of mobile ions.