Composition of Matter:Elements, compounds, and mixtures

Chapter 15.1-pages 450-454

Key Concepts:

Describe a pure substance and a mixture.

Compare and contrast pure substances and mixtures.

List examples of characteristics of elements, compounds and mixtures.

Questions to Ponder:

1. What is an element?2. How is an element different

from an atom?3. How is pure different from

impure?4. What is differences between an

element, compound and mixture?

5. What is the difference between pure and impure substances?

Key Vocabulary:

AtomElementPure substance

CompoundMixture

Imagine a world of Legos:

Composition of Matter: What does

pure mean?

What are the two examples of pure?

All matter is composed of atoms Smallest particle of an element

that still retains the properties of the element ▪ (H, Cl, O)

When we say PURE… ANYWHERE else that you see that

element, it will be EXACTLY the same ▪ Same properties▪ Same number of electrons, protons,

and neutrons Pure substances are either an

ELEMENT or a COMPOUND

Pure Substances: What do you

notice?

SAY WHAT!

What do you already know about atoms and elements??? Write on the post-it note on your desk.

List 3 things that you already know. What do you know?

What is the composition of matter?

Matter

Pure Matter Substance

Impure Matter Mixture

only 1 set of chemical and

physical properties

Each substance in the mixture retains its own

set of chemical and physical properties

Elements: What does

pure mean?

What are some examples of chemical and physical changes?

What is an atom? Where have we seen this before?

An element is a pure substance that cannot be broken down into a simpler substance by physical or chemical means.

All elements are PURE! Means…a substance that is made

of one type of particle ON Periodic Table: shown as only

having 1 capital letter:▪ O for oxygen; C for carbon; Ca for

calcium

Compound: How is this

different from an element?

What makes up compounds?

A compound is a pure substance in which 2 or more elements are joined in a fixed proportion

All c0mpounds are PURE! Means…a substance that is

made of same type of particles

Has 2 or more capital letters Examples: salt, water, rust

Compound:A compound can be

made or broken down into elements through a chemical change. This means…something new is

made that has DIFFERENT properties from the original

Mixture: How is this

different from an element? From a compound?

What makes up mixtures?

How are they made?

A mixture is a material made up of two or more substances (elements or compounds) that can be easily separated by physical means.

All mixtures are IMPURE! Means…a substance that is

made of same type of particles Has 2 or more capital letters

Review:

Matter

Mixture Pure Substance

ElementCompoundHeterogeneous Mixture

Homogeneous Mixture

Can be separated physically

Cannot be separated physically

Can see the parts

Cannot see the parts

Can be separated chemically

Cannot be separated

Most impure Most pure

Summary:

1. How is an element different from an atom?

2. What is differences between an element, compound and mixture?

3. What is the difference between pure and impure substances?