Chapter 3: Matter and Its Changes

Section 1: Physical Properties and Changes

A.Physical property—any characteristic of matter that can be observed or measured without changing the identity of the matter: a physical change makes physical properties change, but their identity remains the same.

Any characteristic that can be observed or measured is a physical property.

•                                                                    Length can be measured.

Any characteristic that can be observed or measured is a physical property.

•                                                               i.      Mass (amount of material in an object) can be measured.

Any characteristic that can be observed or measured is a physical property.

•                                      i.      Volume is a measure of how much space an object takes up;

Any characteristic that can be observed or measured is a physical property.•                                                               i.     

Density is the amount of mass a material has for a given volume.

The same open suitcase on each side. When close d they have the same volume.

But ONE is more dense. Which one?

Would they be the same on a triple beam balance?

Circle the picture that is more Dense.

.

Circle the picture that is more Dense?

• It is not always easy to know by looking at objects. A Coke can and Diet Coke can look alike. If we dropped them both in water (displacement) then the water should rise the same amount for both cans: meaning that they have the same volume.

• But, they could have slightly different masses as we learned in the lab when we used the triple beam balances. This causes them to have different densities. You would find an object’s density by using this formula. D= m/v.

• http://www.youtube.com/watch?v=aR0b4QRhfU0

1.      Density changes as pressure or temperature changes.

Water 15 degreesBall sinks

Water 40 degrees Ball floats

  Physical appearances can be observed (5 senses)

A. Solid, liquid, gas and plasma are four states of matter. An object’s state of matter depends on its temperature and pressure.

• http://myweb.tiscali.co.uk/nickpower/web-content/chempmf.html

• http://www.bbc.co.uk/schools/scienceclips/ages/9_10/gases_fs.shtml

Matter is made up of moving particles. Matter in the plasma phase have the most energy, gas has less than plasma, liquid has less energy than gas, and solids have less energy than

liquids.

• http://www.harcourtschool.com/activity/states_of_matter/

• http://www.bbc.co.uk/schools/scienceclips/ages/9_10/gases_fs.shtml

• http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks3/science/changing_matter/index.htm

1. Melting point—temperature at which a solid becomes a liquid (ice melting)

2. Boiling point—temperature at which a liquid becomes a gas (water boiling)

B. Metallic properties can include luster, malleability, ductility, and magnetism.

C. Physical properties can be used to identify, classify, and separate substances.

D. http://www.bbc.co.uk/schools/scienceclips/ages/9_10/changing_state_fs.shtml

Section 2: Chemical Properties and Changes

A.Chemical Property—characteristic that gives a substance the ability to undergo a change that results in a new substance

• 1.      Flammability

• 2.      Reacts with oxygen, light, water, or other substances

Chemical change—change in the identity of a substance due to its chemical

properties.

• 1.      Signs of a chemical change include the production of bubbles, heat, light, smoke, sounds or color changes.

• 2.      Chemical changes are not reversible using physical means.

• http://www.bbc.co.uk/schools/scienceclips/ages/10_11/rev_irrev_changes_fs.shtml

Law of conservation of mass—mass is never lost or gained in a chemical

reaction.

• 1.      When material is burned, residue is less massive than original material

• 2.      Ash, smoke, and gases escaped into the air—(they are still considered matter.)

• 3.      Their mass was not lost, only relocated.

Example—Physical Change

• Before

• After change

Which one has the greater mass?

Example Chemical Reaction

• Before

During (fire,smoke)

• After change

•

Physical changes… no loss of mass

• http://www.youtube.com/watch?v=YtLEWVu815o