Edexcel IGCSE Physics - States of Matter (VOCABULARY Flashcards)

A set of vocabulary-style flashcards covering states of matter, density, pressure, temperature scales, and related concepts from the notes.

Kinetic Theory

Idea that matter is made of tiny particles in constant motion; the arrangement and motion of particles determine a material’s state and properties.

State of Matter

The form that matter takes (solid, liquid, or gas) determined by particle arrangement and energy.

Solid

State with tightly packed particles in a fixed pattern, giving a fixed shape and fixed volume, with limited vibration.

Liquid

State where particles are less tightly packed, have a fixed volume but take the shape of their container, and are almost incompressible.

Gas

State with widely spaced particles, no fixed shape or volume, highly compressible, moving rapidly and colliding to create pressure.

Density (ρ)

Mass per unit volume (ρ = m/V); units include g/cm³ or kg/m³; represented by the Greek letter rho.

Mass

Amount of matter in an object; typically measured in kilograms or grams.

Volume

The amount of space occupied by an object; measured in m³, cm³, or litres.

Pressure

Force per unit area on a surface (P = F/A); SI unit is the pascal (Pa).

Pascal (Pa)

SI unit of pressure; 1 Pa = 1 N/m².

Melting Point

Temperature at which a solid changes into a liquid.

Freezing

Change of state from liquid to solid; energy released as bonds form.

Condensation

Change of state from gas to liquid; energy released as bonds form.

Boiling

Change of state from liquid to gas when a liquid is heated to its boiling point; bubbles form within the liquid.

Solidification

Another term for freezing; liquid becomes solid.

Heating Curve

Graph of temperature vs time during heating; horizontal sections show energy used to change state rather than raise temperature.

Cooling Curve

Graph of temperature vs time during cooling; horizontal sections indicate energy released during phase changes.

Density of Water

Pure water has a density of about 1.0 g/cm³ (common reference in teaching).

Displacement Method

Determining the volume of an irregular object by measuring the change in water level when the object is submerged.

Displacement Method (Volume of irregular object)

V = final volume − initial volume; used to find the volume of irregular-shaped objects.

Meniscus

The curved surface of a liquid in a container; read measurement at the bottom of the meniscus.

Parallax Error

Reading error caused by viewing the scale from an angle; avoid by reading at eye level.

Specific Heat Capacity (c)

The amount of heat required to raise the temperature of 1 kg of a substance by 1°C (units J/kg·°C).

Heat Energy (Q)

Energy transferred to or from a substance; Q = m c ΔT.

Kelvin Scale

Temperature scale with absolute zero; T(K) = T(°C) + 273.

Absolute Zero

Lowest possible temperature (0 K or −273.15°C) where particle motion ceases.

Boyle’s Law

For a fixed amount of gas at constant temperature, P1V1 = P2V2.

Hydrostatic Pressure

Pressure in a fluid due to the weight of the fluid above; P = ρ g h.

Atmospheric Pressure

Pressure exerted by the Earth's atmosphere at sea level, about 100 kPa.

Floating and Sinking

An object sinks if its density is greater than the surrounding liquid; it floats if its density is less.