chapter 15 section 2 by: kat, cailyn, madison, alyssa, eric (stacy), douglas, shane

Chapter 15Section 2

By: Kat, Cailyn, Madison, Alyssa, Eric (Stacy), Douglas, Shane

Physical Properties• Any characteristic of a material that you can observe without changing the

identity of the substances that make up the material• Appearance-to list the appearances you can list the shape, color, state of

matter, etc. • Behavior-this can include attraction to magnets, ability to be drawn out

into wires, etc. • Using Physical Properties to Separate 1. You can sift out different particles by difference in shape 2. Iron filings can be separated from sand by using a magnet.

Physical Change • Physical change is a change in size, shape, or a state of matter.• The identity remains the same 1. When a substance freezes, boils, evaporates, or condenses, it undergoes physical changes. 2. Changes might involve energy changes, but no identity changes. 3. Color changes may occur too.

Physical Changes (continued)• Using physical changes to separate 1. Evaporating salt water will leave the salt behind• Distillation- the process for separating substances in a mixture by

evaporating a liquid and re-condensing its vapor. 1. It is usually done in a laboratory 2. Used in factories

Chemical properties• Chemical property- A characteristic of a substance that indicates whether

it can undergo a certain chemical change

Detecting Chemical Change• Identity changes 1. Chemical change- a change from one substance to another 2. Rapid release of energy detected as heat, light, and sound 3. Clues such as change in temperature or the formation of bubbles in a liquid are helpful indicators that a reaction is taking place.• Using chemical change to separate 1. Cleaning tarnished silver 2. This type of change is usually used in factories, not at home

Weathering- Chemical or Physical Change

• Physical 1. Rocks split when water seeps into a small crack and freezes 2. The smaller pieces of the rock still have the same properties as before.• Chemical 1. Solid calcium carbonate, a compound found in limestone, reacts when when water is slightly acidic. 2. It changes into a new substance, making it a chemical change.

The Law of Conservation of Mass• Matter is neither created nor destroyed during a chemical change.• The mass of all substances that are present before a chemical change

equals the mass of all the substances that remain after the change.

http://youtu.be/M8tyjwB42X4

^^^physical vs. chemical changes video^^^