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