Section 2 Properties of Matter

Physical Properties Review

• Physical Properties

– Color, size, shape, melting point, strength, hardness, conduction, state change

– Four types of phase changes

• Solids, liquids, gasses, plasmas

Phase Changes: Solids

• Solid-Definite volume and shape

• Couch Potatoes of matter

• Solids have little energy

– Atoms are tightly packed together and do not move much

– Does not assume the shape of the container

Liquid

• Particles are packed closely but can move around each other

• Liquid has no definite shape but has a definite volume

Gas

• Very loosely packed particles

• Lots of energy

– 5 year old hyped on expresso shots

• Gas has no definite shape or volume

Plasma

• Only seen naturally in the sun and lightning

• Electrons have so much energy they leave their nucleus

Terms You Should Know…

• Freezing-Liquid to solid• Melting- Solid to liquid

• Vaporization- Liquid to gas• Condensation-Gas to Liquid

• Sublimation-Solid to Gas• Deposition-Gas to Solid

• Ionization-Gas to Plasma• Recombination-Plasma to Gas

Phase Change Graph

Heat (thermal energy)

Tem

per

atu

re º

C.

100

0

A

B

C

D

E

solid

liquid

gas

Density

• Density-how much matter is in a certain area

– Mass-how much matter

– Volume-how much stuff is in an area

• Therefore…

– Density=mass/volume (g/cm^3)

• So…if you can find mass and volume…you got your density!

Density Problem

• I have an object that has a mass of 113.5kg and a volume of 10cm^3. What is my density?

Certain Objects have certain Densities

• Once density is discovered…you may be able to identify an object

• What is the object we measured the density for before?

Chemical Properties

• Chemical Properties

– Reactivity and Flammability

• OH Yeah!

Chemical and Physical Properties

• Together they form characteristic properties

– Characteristic properties are the properties that form the “character” of a substance

– Describe characteristic properties of water…

Physical and Chemical Changes

• Physical change-changes properties of substance without changing its identity– Can be undone using physical properties

• Chemical Change-Changing a substance into a different substance– Cannot be undone using physical properties

• Is a new substance being created? – No-Physical Change

– Yes-Chemical Change

Physical Change Examples

• Quartz breaks down into sand

– Both SiO₂

– Retains identity

• Has same density, same melting point…etc.

Dissolving

• Is a new substance created?

– I mean sugar just disappears…sounds pretty chemical to me…

• Sugar be separated from water through evaporation (vaporization)

Mixtures

• Can be separated with properties like solubility, magnetism, and density

• Physical changes

• Examples

– Salt water

– Kool Aid

Mixtures Reality Check

• Are heterogeneous mixtures physical or chemical changes?

• Are homogeneous mixtures physical or chemical changes?

• Identify as homogeneous or heterogeneous…

– Colloid

– Solution

– Suspension

Chemical Changes

• Creation of a new substance with different properties

• https://www.youtube.com/watch?v=tLzGW19QhtA

Break out a piece of paper

• Number 1-8

• You need to determine whether the following are physical or chemical changes

Review

Heat (thermal energy)

Tem

per

atu

re º

C.

100

0

A

B

C

D

E

solid

liquid

gas