1. Describing Matter

2. Physical Properties
Physical properties of matter can be observed or measured without changing the identity of the matter.

3. State
The physical form in which a substance exists, such as a solid, a liquid or a gas
Ice is water in its solid state

4. Malleability The ability to be pounded into thin sheets
example Aluminum foil

5. Tensile strength is a measure of how much stress a material can withstand before breaking.

6. Solubility The ability to dissolve in another substance
Sugar dissolves in water

7. Hardness
Hardness measures a solid’s resistance to scratching.

8. Elasticity describes a solid’s ability to be stretched and then return to its original size.
Brittleness is defined as the tendency of a solid to crack or break before stretching very much.

9. A ductile material can be bent a relatively large amount without breaking.
The ductility of many metals, like copper, allow then to be drawn into wire.

10. Density
D=M V
Units- g/mL
g/cm3
kg/m3
kg/L

11. Thermal (Heat)
Thermal Conductivity -Is the rate at which a substance transfers heat
Thermal Expansion-the tendency of atoms or molecules in a substance to take up more space as the temperature increases.

12. Physical Changes
Do not change the identity of a substance and are sometimes easy to reverse
Examples:butter can be melted and then it can be put in the refrigerator to reverse the change
Water can be frozen and then melted

13. More Examples of Physical Changes
Melting ice cubes
Sanding a piece of wood
Cutting hair
Crushing a can
Bending a paper clip
Mixing oil and vinegar

14. 12.1 Properties of Solids
Properties that can only be observed when one substance changes into a different substance are called chemical properties.
Any change that transforms one substance into a different substance is called a chemical change.

15. Chemical Properties Flammability
Reactivity (with water, acid, or oxygen)
Electrolysis

17. Chemical Changes
Any time there is a chemical change, a chemical reaction has occurred.

18. CLUES TO CHEMICAL CHANGES
Bubbling - a new gas is formed
Turns cloudy- a precipitate is formed
A precipitate is a solid that is insoluble in the reaction mixture

19. CLUES TO CHEMICAL CHANGES
Change in color – a new substance is forming
Change in temperature – energy is being released or absorbed

20. Types of Solids
The atoms or molecules in a solid are arranged in two ways.
If the particles are arranged in an orderly, repeating pattern, the solid is crystalline.
If the particles are arranged in a random way, the solid is amorphous.

21. Examples
Amorphous
Rubber
Wax
Glass
plastics
Crystalline
Salts
metals