What is Matter?

Physical ScienceChapter 2

Matter

• Anything that has mass and takes up space

• All the materials you can hold or touch

• Examples– You– This computer– The air you are breathing

Atoms

• Atoms are matter

• Atom = smallest particle that has the properties of an element

• Atoms make up elements

Elements

• Element = a substance that cannot be broken down into simpler substances

• An example of an element is carbon

• So, carbon is an element and elements are made of atoms

Elements

• Each element has a one or two letter symbol

• Each are unique and behave differently

• What element is shown here?

Compounds

• Most substances exist on Earth and in the human body as compounds, not free elements

• A compound is a substance made of more than one element bound together

Carbon = black

Oxygen = red

Hydrogen = white

Compound Properties

• Specific compounds always combine in the same proportions– Every water molecule has 2 hydrogens and 1

oxygen

• Compounds have properties very different from their individual elements

+ =

Chemical Formulas

• Contains the symbols for each element in a compound and the numbers for each atom of each element

• H2O

• CO2

• CH4

• NaCl

Pure Substances

• Matter with a fixed composition and definite properties

• Examples are atoms, elements, and compounds

• Cannot be separated by physical actions

Mixtures

• NOT PURE SUBSTANCES

• Made of pure substances, but composition is not fixed

• Can be separated by physical actions

+ + =

Types of Mixtures

• Heterogeneous = substances are not uniformly mixed throughout, you can see the layers

• Homogeneous = evenly mixed throughout– Layers are not visible– Also called a solution

More Mixtures

• Gases can also mix with liquids

• Gases are usually dissolved in water

• Examples are carbonated drinks– Homogeneous mixtures (solutions)– Contain sugar, flavorings and carbon dioxide

dissolved in water