The Structure of The Structure of The AtomThe Atom

Chapter 2Chapter 2

Matter and SubstanceMatter and Substance

Matter is anything that has mass and Matter is anything that has mass and occupies space.occupies space.

Made up of Made up of tiny and discrete tiny and discrete particlesparticles ( (atoms, molecules and ionsatoms, 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 matterKinetic theory of matter

Explain the energy and forces between Explain the energy and forces between particles in matterparticles in matter

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

particles gain particles gain more kinetic energymore kinetic energy and move and move in in greater speedsgreater speeds..

tinyspeed

higher

DiffusionDiffusion

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

Occurs in gases, _______ and solids.Occurs in gases, _______ and solids.

occupy

liquids

Diffusion – Brownian MotionDiffusion – Brownian Motion

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

direction collision

Diffusion – Brownian MotionDiffusion – Brownian Motion

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

in waterin water

DiffusionDiffusion

Diffusion in solid, liquid and gasDiffusion in solid, liquid and gas

Diffusion in solid, liquid and gasDiffusion in solid, liquid and gas

SOLIDSOLID

Arrangement Arrangement of particlesof particles DescriptionDescription PropertyProperty

Particles are held together Particles are held together by very strong _______ of by very strong _______ of attractionattraction

Cannot be Cannot be compressedcompressed

Closely packed together in Closely packed together in an orderly ________ an orderly ________

Has a fixed Has a fixed shape and shape and volumevolume

The kinetic energy of the The kinetic energy of the particles is _____.particles is _____.

Particle can vibrate and Particle can vibrate and rotate in their fixed rotate in their fixed position.position.

--

forcesforces

mannermanner

lowlow

LIQUIDLIQUID

Arrangement Arrangement of particlesof particles DescriptionDescription PropertyProperty

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

Cannot be Cannot be compressed compressed easilyeasily

Packed closely but not in Packed closely but not in an orderly ________ an orderly ________

Has a fixed Has a fixed volume and volume and takes the shape takes the shape of its containerof its container

The kinetic energy of the The kinetic energy of the particles is greater than in particles is greater than in ______ state. ______ state.

Particle can vibrate, rotate Particle can vibrate, rotate and move.and move.

--

weakerweaker solidsolid

mannermanner

solidsolid

GASGAS

Arrangement Arrangement of particlesof particles DescriptionDescription PropertyProperty

______ forces of attraction ______ forces of attraction between particlesbetween particles

Can be Can be compressed compressed easilyeasily

Particles are very _____ Particles are very _____ apart from each other.apart from each other.

Has no fixed Has no fixed volume and volume and takes the shape takes the shape of its containerof its container

The particles have very The particles have very ________ kinetic energy. ________ kinetic energy.

Particles can move freely Particles can move freely in ________ motion.in ________ motion.

--

WeakWeak

farfar

highhigh

randomrandom

Inter-conversion of matterInter-conversion of matter

Gas

LiquidSolidA

BC

D

EF

Heating

Cooling

Changes in the state of matterChanges in the state of matter

MeltingA

BoilingB

SublimationC

Inter-conversion process

D Freezing

E Condensation

F Sublimation

Inter-conversion ProcessesInter-conversion Processes

ProcessProcess DescriptionDescriptionMeltingMelting Solid to liquid, heat is absorbed, particles gain energy Solid to liquid, heat is absorbed, particles gain energy

and vibrate vigorously to break away from their fixed and vibrate vigorously to break away from their fixed position.position.

Evaporation / Evaporation / BoilingBoiling

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

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

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

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

The heating curve of a substanceThe heating curve of a substance

Temperature (°C)

Time (Min)

Boiling pointBoiling point

Melting pointMelting point

A

B C

D E

F

The cooling curve of a substanceThe cooling curve of a substanceTemperature (°C)

Time (Min)

Boiling pointBoiling point

Freezing pointFreezing point

U

TS

RQ

P

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