Grade 9 Science– Notre Dame College School

John Dalton – the guy who came up with particle theory

AgendaWhat is matterThe Particle TheoryMixtures vs. Pure SubstancesMixtures

Hetrogeneous Mixtures Solution

Homogeneous Mixtures Mechanical Mixture Suspension SolutionPure Substances

Elements Compounds

What is Matter?Matter is anything that contains mass &

volume (takes up space)Energy, such as light, heat, and sound, is

NOT matter

IT’S ALL MATTER!

The Particle Theory of Matter This provides a way to describe the

structure and behaviour of matter. There are 4 principals of the particle theory

written by a chemist named John Dalton.

Think About it!Look at a piece of chalk If you broke a piece of chalk in half, would it still look like and behave like chalk?How small of pieces would you have to break a piece of chalk so that it isn’t chalk anymore – is that even possible? The answer is YES, because the smallest pieces of chalk are made up of particles and the particle theory explains how this works!

The Particle Theory of Matter1. All matter is made up of very tiny

objects called particles. These particles are VERY tiny – too small

to be seen with any regular light microscope

The Particle Theory of Matter2. All Particles

have spaces between them.

The size of these spaces determine the state of the matter

The Particle Theory of Matter3. Particles present in matter are always in

motion. In a solid, they vibrate together In a liquid, they stay close together but slide

along each other In a gas, they bounce and move in all directions!

The Particle Theory of Matter4. The particles in a substance attract each

other. The degree that particles are attracted to each

other is different in difference substances,

Take a guess! Which substance do you think has the strongest

attractions? Which has the weakest? Iron Water Oxygen

The Particle Theory of MatterRecap: Here they are all again

1. All matter is made up of very tiny objects called particles.

2. All particles have spaces between them.3. Particles present in matter are always in

motion.4. The particles in a substance attract each other.

Pure Substances vs. MixturesAll matter can be divided into two big

categories: PURE SUBSTANCES and MIXTURES.Pure substances are made up of one type of

element or compoundMixtures are a combination of pure

substances (2 or more types of particles)

Versus

Pure SubstancesPure substances are made up of only

ONE type of particlePure substances are in the form of either

elements or compounds.

ElementsElements are the smallest and

“purest” forms of particlesThey cannot be broken down

further by ordinary means (such as simple reactions, heat, or electricity)

They are only made up of one type of atom (one type of particle)

Examples are Oxygen, Calcium, Iron, Carbon and Helium

Compounds

Water is a molecule because it is made out of two types of atoms (oxygen and hydrogen)

OxygenHydrogen

HydrogenWater is a compound because it has many molecules of one type (H2O = Water)

A compound is made up of only one type of particle, called a molecule

Compounds are made up of many molecules that are held together by chemical bonds!

MixturesA mixture is a combination of two or more

different substances (different types of particles).

Mixtures can be divided into 2 big categories:Heterogeneous MixturesHomogeneous Mixtures

Heterogeneous MixturesMade up of two or more

particles where the different particles are easy to see and separate.

Can be divided into two categories:Mechanical mixturesSuspensions

An Oreo cookie is a heterogeneous mixture

Mechanical MixturesParticles that are in the same container but

can be easily separated.Made up of several distinct parts

A lasagne, parfait, and a cookie are both examples of

mechanical mixtures

THINK ABOUT IT!What are some of the

parts of these mechanical mixtures?

SuspensionsSmall particles of one

substance float in another substance

Salad Dressing, glittery nail polish,

and yogurt are examples of suspensions

Homogeneous MixturesA homogenous mixture

occurs when 2 or more particles blend together and cannot be seen separately

Solutions are homogeneous mixtures!

SolutionsA mixture of 2 or more

things where one substance dissolves

Kool-Aid and tea are solutions because you cannot see the flour crystals floating in the Kool-Aid, and you cannot see the tea floating in the tea when the bag is removed Kool-Aid and tea

are examples of solutions