Science Revision: Matter & Mixtures

Kinetic Theory

• All matter is made of tiny particles.

• Particles are always moving.

• Heat is directly proportional to the speed of the movement of the particles.

• The state of matter depends on the energy and movement of its particles.

States of Matter

• Solid:

  • Has a fixed shape.

  • Particles are tightly packed.

• Liquid:

  • Takes the shape of its container.

  • Particles can slide past each other.

• Gas:

  • Fills the available space.

  • Particles move freely.

Change of State

• cMelting: The process by which a solid becomes a liquid.

• Freezing: The process by which a liquid becomes a solid.

• Boiling: The process by which a liquid becomes a gas.

• Condensation: The process by which a gas becomes a liquid.

• Sublimation: The process by which a solid directly becomes a gas.

Pure Substances

• Made of only one kind of particle.

• Have a fixed boiling point and melting point.

• Examples: Water $(H<em>2O)$, gold $(Au)$, and oxygen $(O</em>2)$.

Impure Substances

• Made of different substances.

• Do not have a fixed boiling point or melting point.

• Examples: Air and salt water.

Separation of Mixtures

• Filtration: Used to separate a solid from a liquid.

• Evaporation: Used to separate a solute from a solution.

• Distillation: Used to separate liquids or a solution.

• Sieving: Used to separate large particles.

• Chromatography: Used to separate different colors or substances with different affinities.

Temperature Scales

• Celsius (°C): The scale ranges from 0°C to 100°C.

• Kelvin (K): The scale ranges from 273 K to 373 K.

• Fahrenheit (°F): The scale ranges from 32°F to 212°F.

• Usage:

  • Kelvin is primarily used in science.

  • Celsius and Fahrenheit are used in daily life.

Quick Recap

• Matter is made of moving particles.

• Heat changes the states of matter.

• Mixtures can be separated using various techniques.

• Temperature can be measured in °C, K, and °F.