2.1 Models of Matter2.1 Models of Matter

The Particle TheoryThe Particle Theoryp. 44p. 44

Building Blocks of MatterBuilding Blocks of Matter

Like Lego, all matter is made of small Like Lego, all matter is made of small pieces that are called pieces that are called ParticlesParticles

Particles can be arranged in many Particles can be arranged in many different ways, but no matter how we different ways, but no matter how we group particles, they will either be a pure group particles, they will either be a pure substance, or mixture.substance, or mixture.

1. Pure Substances1. Pure Substances

A pure substance contains only A pure substance contains only oneone type type of particle.of particle. Aluminum foil – contains only aluminum.Aluminum foil – contains only aluminum. Jar ‘A’ – contains only red M & M’s.Jar ‘A’ – contains only red M & M’s. Table Salt – contains only NaCl (sodium Table Salt – contains only NaCl (sodium

chloride) particles.chloride) particles.

2. Mixtures2. Mixtures

A mixture contains A mixture contains at least two different at least two different pure substancespure substances.. Pizza – has bread, sauce, cheese, and other Pizza – has bread, sauce, cheese, and other

toppings.toppings. Jar ‘B’ – contains different coloured jelly Jar ‘B’ – contains different coloured jelly

beans.beans. Jar ‘C’ – contains Crystal Light drink mix.Jar ‘C’ – contains Crystal Light drink mix.

Classifying MixturesClassifying Mixtures

Not all mixtures are the same, as we saw Not all mixtures are the same, as we saw with the Jelly Beans and the Drink Mix.with the Jelly Beans and the Drink Mix.

Solution (Homogeneous Mixture)Solution (Homogeneous Mixture) When substances mix together so well that When substances mix together so well that

they look like one substance.they look like one substance. Jar ‘C’ – it looks like one substance even Jar ‘C’ – it looks like one substance even

though it contains water and drink mix.though it contains water and drink mix. Jar ‘D’ – water and oil are Jar ‘D’ – water and oil are insolubleinsoluble - they - they

don’t mix at all.don’t mix at all.

Classifying MatterClassifying Matter

Heterogeneous MixtureHeterogeneous Mixture When the parts of the mixture can be easily When the parts of the mixture can be easily

seen.seen. Jar ‘B’ – each of the various types of jelly Jar ‘B’ – each of the various types of jelly

beans can be clearly seen.beans can be clearly seen.

The Particle TheoryThe Particle Theory

We’ve just described the first two We’ve just described the first two principles of the Particle Theory:principles of the Particle Theory:

1.1. All matter is made up of tiny particles.All matter is made up of tiny particles.

2.2. All particles of one substance are the All particles of one substance are the same. Different substances have different same. Different substances have different particles.particles.

The Particle TheoryThe Particle Theory

The next two principles of the Particle The next two principles of the Particle Theory explain how particles interact with Theory explain how particles interact with one another.one another.

What happens when you are low on What happens when you are low on energy?energy?

The Particle TheoryThe Particle Theory

Now, if you have a little more energy …Now, if you have a little more energy …

Even more energy! You’ve just had Even more energy! You’ve just had three ‘Red Bulls’ . . . three ‘Red Bulls’ . . .

The Particle TheoryThe Particle Theory

Principle three states:Principle three states:3.3. The particles are always moving, and the The particles are always moving, and the

more energy they have, the faster they more energy they have, the faster they move.move.

This is why when we heat substances, This is why when we heat substances, they can change from Solid – Liquid – they can change from Solid – Liquid – Gas, we’ve added energy.Gas, we’ve added energy.

The Particle TheoryThe Particle Theory

Similar to how the earth has gravity, and Similar to how the earth has gravity, and attracts other things to it, attracts other things to it, particles attract particles attract other particlesother particles..

Do you think cooler, less energetic Do you think cooler, less energetic particles will attract as strongly as hotter particles will attract as strongly as hotter and more energized particles?and more energized particles?

The Particle TheoryThe Particle Theory

What you’ve just described is the fourth, What you’ve just described is the fourth, and final principle!and final principle!

4.4. There are attractive forces between the There are attractive forces between the particles. These forces are stronger when particles. These forces are stronger when the particles are closer together.the particles are closer together.

What are these particles?What are these particles?

What is a substance called if we can no What is a substance called if we can no longer break it down into smaller longer break it down into smaller particles?particles? Examples of these particles are Aluminum, Examples of these particles are Aluminum,

Oxygen, Hydrogen, Rhodium, Zinc, etc.Oxygen, Hydrogen, Rhodium, Zinc, etc. These are called . . .These are called . . .

ELEMENTSELEMENTS!!!! Elements are pure substances that cannot Elements are pure substances that cannot

be broken down into simpler substances.be broken down into simpler substances.

What are these particles?What are these particles?

What if we have two or more elements What if we have two or more elements combined in a fix amount?combined in a fix amount? Examples of these include NaCl, HExamples of these include NaCl, H22O, and O, and

COCO22.. These are called . . .These are called . . .

COMPOUNDSCOMPOUNDS!!!! Compounds are substances that contain two Compounds are substances that contain two

or more different elements in a fixed or more different elements in a fixed proportion.proportion.

Naming the ‘Particles’Naming the ‘Particles’ The particles referred to by scientists are The particles referred to by scientists are

called called atomsatoms.. Each element is made of only one type of Each element is made of only one type of

atom.atom. Atoms can combine with each other to Atoms can combine with each other to

form form moleculesmolecules.. Molecules can contain 2 atoms, or many Molecules can contain 2 atoms, or many

thousands of atoms.thousands of atoms.

QuestionsQuestions

Page 47, questions 2, 3 & 4Page 47, questions 2, 3 & 4