Physical Science Chapter 9 Classification of Matter Physical


Physical Science Chapter 9 Classification of Matter

Physical Properties of Matter

-property – characteristic of a substance that describes an object

-physical property – characteristic of matter that can be observed without changing it

-color, shape, density, hardness, boiling/freezing pt, odor, etc.

-does not involve a change to something new

-chemical property- characteristic that determines how substance reacts to form other


-involves a change to something new

-corrosion – destruction of metal because it combines chemically with other substances

Changes in Matter

-all changes involve an energy change

- Law of Conservation of Matter- matter cannot be gained or lost during a chemical change

-physical changes- a change in the size, shape, color, or state of matter (solid, liquid, ice)

-it only changes it’s appearance, not the actual substance

-chemical changes – change in a substance that produces a NEW substance with different


-electrolysis: a chemical change produced by an electrical current

-electricity can separate the hydrogen and oxygen in water

-‘lysis’ means to break down

-clues that a chemical change has occurred :

-heat or light given off

-bubbles produced

-sound given off

-odor is produced

Composition of Matter

Matter- anything that has mass & takes up space

Pure substance: Matter in which all the particles are alike

-only 2 substances in science are:

1. Elements

2. Compounds

Element = matter that has only 1 type of atom (atoms make up elements)

Atoms= Building blocks of all matter – smallest part of element

-chemical symbols – representation for elements

- 1 or 2 letters; 1 st

capitalized, 2 nd

isn’t = Ca

-some symbols are for the Latin name - Au = Aurum (gold)

- elements are found on the Periodic Table

Compound – matter made of 2 or more elements chemically joined together, ALWAYS IN THE SAME


-water is ALWAYS H


O, not H




or H


- molecules = made up of 2 or more atoms chemically combined

- smallest part of a compound



- water always has 2 Hydrogen and 1 oxygen

Mixtures – 2 or more elements or compounds that are blended, not chemically combined

-each part keeps its own properties

-can be combined in ANY ratio – 1 cup sand and 1 gallon salt or vice versa – doesn’t matter

-2 types

-Heterogeneous mixture: substances are not spread evenly throughout mixture

- pizza, chocolate that settles in bottom of cup, city air (smog particles),paint- oil

floats on top and has to be mixed in,

-Homogeneous mixture: substance are spread evenly throughout the mixture

-milk, pure water, flat pop, any element or compound

Differences between Compounds & Mixtures





Elements combined in certain ratio (H

Elements chemically combined




Parts can be combined in any ratio

Parts physically combined

Compound has different properties from its elements Parts keep their own properties

Solutions, Suspension & Colloids

Solution: Homogeneous mixtures made of more than 1 substance –don’t settle or scatter light

2 parts:

1. solvent = substance DOING the dissolving

2. solute = substance BEING dissolved

-soluble: means it CAN be dissolved like salt in water

-insoluble: means it CAN’T be dissolve like oil in water or metal in water

Alloy = a solution made of metals that improves its properties, or produces a desired property


Many uses in automotive, aerospace, construction, medical, manufacturing areas





Bronze was the first alloy discovered – made of copper and tin

Brass – alloy made of copper & zinc

Steel – alloy made of iron and carbon (pure carbon = diamond)

Types of alloys

-Aluminum alloys – strong and lightweight

-Copper alloys – excellent thermal and electrical performance

-Nickel alloys- good corrosion and thermal resistance

-Titanium alloys= very strong, tough and corrosion resistant

-stainless steel alloys-very corrosion resistant





HETEROgeneous mixture in which particles are large enough to be seen

Gravity makes ‘suspended’ particles settle

Can separate parts using filter paper




Mixtures with particles larger than solution, but smaller than suspension

Does NOT settle


Scatters light – cloudy looking

-Tyndall effect – ability of a colloid to scatter light

-beam of light in smoke, dust

-beams of light coming off street lights in winter on icy nights

-Brownian motion- Random motion of particles in a colloid

-dust particles swirling around (seen in sunlight beams)

-coagulation – the clumping together of particles

-destroys colloids – particles stick together and unable to stay suspended

-emulsifier- substance that allows colloids to stay mixed – egg keeps oil/water mixed in mayo

Types of Colloids

1. Foam – whipped cream, soap suds, marshmallow

2. Aerosol = fog, clouds

3. Emulsion = milk, mayo, cheese

4. Smoke = particles in air

5. Sol = jelly, pearls