S4.1.1 Glossary Flashcards
Atom
The smallest part of matter
Boiling
When a liquid becomes a gas when it is heated
Boiling point
The temperature at which a substance boils
Bonding
How atoms are chemically joined together
Change of state
When a substance changes from one state to another
Chemical change
An irreversible change in a substance to form a new product
Condensing
When a gas cools to become a liquid
Density
A measure of a substance’s mass per unit volume
Evaporation
When a liquid is heated to become a gas
Freezing
When a liquid cools to become a solid
Gas
A state of matter with particles which are spread far apart
Gas pressure
A force exerted by gas particles colliding with the walls of a container
Impure
A substance containing more than one element or compound
Kinetic energy
The energy store of moving objects
Kinetic theory
The rapid, constant motion of particles in a gas
Liquid
A state of matter with particles that can flow over one another
Mass
A measure of the amount of matter in an object
Melting
When a solid is heated to become a liquid
Melting point
The temperature at which a substance melts
Mixture
Substance containing more than one element or compound
Molecule
Substance made of more than one atom joined together
Physical change
A reversible change where a substance changes state
Pure substance
Substance containing only one element or compound
Solid
A state of matter with particles in fixed positions
Specific heat capacity
Energy required to heat 1kg of a substance by 1°C
Specific latent heat
Energy required to change the state of 1kg of a substance, without changing temperature
SLH of fusion
Energy required to melt 1kg of a substance, without changing temperature
SLH of vaporisation
Energy required to evaporate 1kg of a substance, without changing temperature
Sublimation
When a solid becomes a gas, without becoming a liquid first
Thermal energy
The energy store of hot objects
Volume
A measure of the space an object takes up
