Chapter 15 Section 1

Matter Materials are made of a ______________

substance or a ______________ of substances. Pure Mixture

What is a substance? Type of matter with a fixed composition

Matter What are the two types of substances

we can have? Element Compound

Elements What is an element?

All the atoms in a substance are the same

Look at the periodic table what are some common elements? Oxygen, Hydrogen, Copper, Zinc

Elements Are all elements found on Earth?

90 elements found on Earth

20 have been made in the lab

Do the elements made in the lab last a long time? No, they are unstable and exist for only a

short period of time

Compounds Define Compound:

2 or more elements that have combined together to form a substance

The elements are present in a fixed proportion.

Water has 2 atoms of Hydrogen and 1 atom of Oxygen

Mixtures What are the two types of mixtures?

Homogeneous

Heterogeneous

What is the difference between these two types of mixtures?

Mixtures When you make soup does it always

contain the same amount of each ingredient each time?

No because mixtures do not always contain the same proportions of substances that make them up.

Mixtures Heterogeneous mixture:

Mixture in which different materials can easily be distinguished.

Examples: Pizza toppings Dry soup mixes Clothing fabrics when looked at under a

microscope

Mixtures Homogeneous mixture:

Contains 2 or more gaseous, liquid, or solid substances blended evenly throughout

Examples:1. Pop2. Vinegar

Mixtures Solution:

Homogeneous mixture of particles so small that they cannot be seen with a microscope and will never settle to the bottom of their container.

Remain constantly and uniformly mixed

Colloid What is a colloid?

A specific kind of mixture

Like a heterogeneous mixture it contains varying proportions of its components

Like a solution the components won’t settle out

Colloid Colloid:

Type of mixture with particles that are larger than those in solutions but not heavy enough to settle out

Colloid is the Greek word for glue

Examples: Paint Fog

Detecting Colloids How can you tell a colloid from a

solution?1. Appearance : If you can pass a light

beam through it then it is a colloid Light beams are invisible through a

solution

This occurs because the particles in a colloid are large enough to scatter light.

Tyndall effect

Suspensions Some mixtures are neither solutions or

colloids Ex: Pond Water

Suspension: Heterogeneous mixture containing liquid

in which visible particles settle Ex: River Deltas

Description Solution Colloid Suspension

Settle upon standing?

No No Yes

Separate using filter paper?

No No Yes

Particle Size

0.1-1 nm 1-1000 nm Greater than 1000 nm

Scatter light

No Yes Yes