Today we will ...

• Describe matter

• Talk about the properties of the different states of matter

• Describe elements

• Review Atomic Strucutre

Review of Atomic Structure

​Warm-Up

On the Sheet of paper write down some words that you think about when you hear the word chemistry.

Try and refer to what you learned in Gr 9 science

What is Chemisty?

the study of matter and chemical changes

What is Matter?

Key Concept:

Matter is anything that has mass and takes up space.

Matter can be described in terms of its volume, mass and weight.

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​Understanding what matter is and how units are used to describe matter can help you understand the structure of the physical world.

What is matter?

Anything that has mass and takes up space.

You are surrounded by it and much of what you are made up of it has matter

Can you think of anything that doesn't have mass or doesn't take up space?

Moving between the states of matter

All matter is either a pure substance or a mixture of substances.

(Most everyday items are mixtures)

All matter is composed of atoms.

Atoms are the "building blocks" of the universe

Key Concept:

Matter is made up of elements

An Element

A substance composed of only one type of atom.

Multiple atoms of the same type can be bonded together.

Elements cannot be broken down by chemical means.

A Compound

A substance composed of 2 or more elements chemically bonded.

Component elements have a definite ratio (E.g. 2:1 for H:O in water)

Compounds can be separated by chemical means into their component elements.

Mixtures

• Component substances can be separated by physical means.

• Component substances retain their original properties.

Calculating subatomic particles:

# of protons = atomic number

# electrons = # of protons (atomic number)

# neutrons = atomic mass – atomic number

Note: Mass is the rounded off value of the atomic weight to a whole number

chemical reactivity of an element is determined by the # of electrons in the outer shell = valence electrons

Look at the chart of Chemical compounds and practice questions. You may complete with your group