The Structure of The Atom

Chapter 2

Matter and Substance

Matter is anything that has mass and occupies space.

Made up of tiny and discrete particles (atoms, molecules and ions)

Atoms

Molecules

Ions

The smallest particle, which can participate in a chemical reaction

Group of two or more atoms which are chemically bonded together

Positively or negatively charged particles

Kinetic theory of matter

Explain the energy and forces between particles in matter

Three basic assumptions:– Matter is made up of _____ particles.– The tiny particles are in constant ______.– When the temperature is _______, the

particles gain more kinetic energy and move in greater speeds.

tinyspeed

higher

Diffusion

A process in which the particles of substance move and _________ the spaces in between the particles of another substance.

Occurs in gases, _______ and solids.

occupy

liquids

Diffusion – Brownian Motion

The movement of particles in all _______ caused by the _______ among the particles or between particles and the container wall.

direction collision

Diffusion – Brownian Motion

Examples:– Movement of smoke particles in air– Movement of pollen grains in water– Pouring concentrated sugar solution

in water

Diffusion

Diffusion in solid, liquid and gas

Diffusion in solid, liquid and gas

SOLID

Arrangement of particles Description Property

Particles are held together by very strong _______ of attraction

Cannot be compressed

Closely packed together in an orderly ________

Has a fixed shape and volume

The kinetic energy of the particles is _____.Particle can vibrate and rotate in their fixed position.

-

forces

manner

low

LIQUID

Arrangement of particles Description Property

The forces of attraction between particles are _______ than in ________ but stronger than in gas state

Cannot be compressed easily

Packed closely but not in an orderly ________

Has a fixed volume and takes the shape of its container

The kinetic energy of the particles is greater than in ______ state. Particle can vibrate, rotate and move.

-

weaker solid

manner

solid

GAS

Arrangement of particles Description Property

______ forces of attraction between particles

Can be compressed easily

Particles are very _____ apart from each other.

Has no fixed volume and takes the shape of its container

The particles have very ________ kinetic energy. Particles can move freely in ________ motion.

-

Weak

far

high

random

Inter-conversion of matter

Gas

LiquidSolidA

BC

D

EF

Heating

Cooling

Changes in the state of matter

MeltingA

BoilingB

SublimationC

Inter-conversion process

D Freezing

E Condensation

F Sublimation

Inter-conversion Processes

Process DescriptionMelting Solid to liquid, heat is absorbed, particles gain energy

and vibrate vigorously to break away from their fixed position.

Evaporation / Boiling

Liquid to vapour, heat is absorbed, particles gain enough energy to break away completely from the liquid to form steam.

Sublimation Solid to vapour, heat is absorbed, particles get enough energy to break away completely from the solid and form a gas.

Freezing Liquid to solid, heat is liberated, particles slow down their vibration and stop moving.

Condensation Vapour to liquid, heat is liberated, particles lose energy and move more and more slowly to form liquid.

The heating curve of a substance

Temperature (°C)

Time (Min)

Boiling point

Melting point

A

B C

D E

F

The cooling curve of a substanceTemperature (°C)

Time (Min)

Boiling point

Freezing point

U

TS

RQ

P