Matter In Our Surroundings

Vocabulary flashcards covering key terms and definitions related to matter, its states, properties, and changes as discussed in the lecture notes.

Matter

Anything that has mass and occupies space; the universe is made up of matter.

Panch Tatva

Ancient Indian classification of matter into five elements: air, earth, fire, sky, and water.

Mass

The amount of matter in an object; SI unit is the kilogram (kg).

Volume

The space occupied by a substance; SI unit is cubic metre (m3); common unit is litre (L). 1 L = 1 dm3 = 1000 mL; 1 mL = 1 cm3.

Density

Mass per unit volume; density = mass/volume; SI unit is kg/m3.

Matter is made of Particles

Matter is made up of tiny particles that occupy spaces between one another.

Space Between Particles

There is empty space between particles, allowing diffusion and mixing of substances.

State of Matter

The forms in which matter exists: solid, liquid, and gas.

Solid

A state with definite shape and volume, low compressibility, and rigid structure.

Liquid

A state with definite volume but no fixed shape; takes the shape of its container and flows.

Gas

A state with no fixed shape or volume; fills the container and is highly compressible.

Inter-particle Forces

Attractions between particles; these forces are strongest in solids and weakest in gases.

Kinetic Energy

Energy of motion of particles; increases with temperature, causing faster movement.

Diffusion

Spontaneous mixing of substances as particles spread into spaces between others; faster at higher temperatures.

Melting Point

The temperature at which a solid changes to a liquid at atmospheric pressure.

Fusion

Another term for melting; solid to liquid phase change.

Boiling Point

The temperature at which a liquid changes to a gas at atmospheric pressure; boiling is a bulk process.

Latent Heat of Fusion

Heat required to change 1 kg of solid into liquid at its melting point, without a temperature change.

Latent Heat of Vaporisation

Heat required to change 1 kg of liquid into gas at its boiling point, without a temperature change.

Evaporation

Liquid-to-gas change that occurs at any temperature below boiling point; a surface phenomenon influenced by surface area, temperature, humidity, and wind.

Sublimation

Direct change of a solid to a gas without passing through the liquid state.

Deposition

Direct change of a gas to a solid without passing through the liquid state.

Compressibility

The ease with which a substance can be compressed; gases are highly compressible, solids are not (with some exceptions like sponge).

Fluidity

The ability to flow; liquids and gases are fluids.

Pressure

Force per unit area; SI unit is pascal (Pa); atmosphere (atm) is a common reference unit (1 atm ≈ 1.01×105 Pa).

Atmospheric Pressure

The pressure exerted by the atmosphere at sea level, about 1 atm.

Diffusion Rate

The speed at which particles spread through a medium; faster in gases, slower in solids.

Temperature Scales (Kelvin and Celsius)

Kelvin (K) and degree Celsius (°C); 0°C = 273 K; conversion between scales involves adding or subtracting 273.

Inter-particle Space

The spaces between particles that allow diffusion and mixing of substances.