1. 14-1 – Matter and Thermal Energy
Classifying Matter

2. 14-1 – Matter and Thermal Energy
Kinetic Theory of Matter
All matter is composed of tiny particles
These particles are in constant, random motion
The particles collide with each other and with the walls of any container in which they are held
The amount of energy that the particles lose from these collisions is negligible.

3. 14-1 – Matter and Thermal Energy
Kinetic Molecular Theory
Explains why matter changes states
Matter changes states due to gain or loss of energy
Explains why a particular state behaves as it does
Objects expand when heated
Explains why the temperature of a substance increases as you heat it
Temperature of an object is a measure of the average kinetic theory of a substance

4. 14-1 – Matter and Thermal Energy
Anything with mass that takes up space (volume) is matter.
Exists in 4 states
Solid
Liquid
Gas
Plasma

5. 14-1 – Matter and Thermal Energy
Solid:
The particles of a solid are in a tight, fixed position. Since the particles in solids are not free to move around they vibrate just a little. Solids have a set volume and a set shape.

6. 14-1 – Matter and Thermal Energy
Liquid:
The particles of a liquid are close together, but they are not in a neat arrangement like in a solid. They have enough space to slide past each other. Liquids have a set volume but no set shape.

7. 14-1 – Matter and Thermal Energy
Gas:
The particles of a gas have a lot of space between them. They move fast and in no order. The volume of gas also increases as temperature increases. Gasses have no set volume and no set shape.

8. 14-1 – Matter and Thermal Energy
Plasma:
Contains particles that are positively and negatively charged. Atoms begin to lose electrons, creating charged particles that move freely. Plasma, like a gas, has no set volume or shape and can be found in stars, Plasma TVs, and neon signs.

9. 14-1 – Matter and Thermal Energy
Changes of state
Melting point –
Melting –
Heat of fusion –
Freezing point –
Freezing -

10. 14-1 – Matter and Thermal Energy
Changes of state
Boiling point –
Evaporation –
Heat of vaporization –
Condensation -
Sublimation-

11. 14-1 – Matter and Thermal Energy
Heating Curves
A graph of temperature vs. time for heating a substance

12. 15-1 – Classification of Matter
Pure Substances
Elements –
Element and atom are not the same
Periodic Table of Elements
Compounds –
Made from combined elements

14. 15-1 – Classification of Matter

15. 15-1 – Classification of Matter
Bromine (Br2) and Oxygen (O2) exist naturally as molecules. Each molecule consists of two atoms bonded together. Even though it is made of molecules it is still an element because it contains only one type of atom.

16. 15-1 – Classification of Matter
Element or Compound??
H20
Copper (Cu)
C6H12O6
NaCl
Oxygen (O2)
Sodium (Na)

17. 15-1 – Classification of Matter
Mixtures-
Heterogeneous Mixtures –
Homogeneous Mixtures-
Solutions-

18. 15-1 – Classification of Matter
Classify the following as an element, compound, or mixture. If mixture, make sure to label homogenous or heterogeneous.
1) soda 4) Nitrogen (N)
2) water (H20) 5) NH4
3) gravel 6) a taco

19. 15-2 – Properties of Matter
Physical properties
Physical properties are characteristics of a substance that can be measured without changing the identity of the substance.
Appearance (for example, color or shape)
Odor
Melting point and boiling point
Density
Hardness
Ductility and Malleability (ability to change shape)
Solubility
Electrical and thermal conductivity
Magnetism

20. 15-2 – Properties of Matter
Chemical properties
characteristics of a substance that describe the ways it can react to form new materials.
Chemical properties cannot be measured or studied without changing the composition of the substance.
Flammability and other tendencies to react with oxygen
Reaction with acids and bases
Reaction with water
Decomposition caused by light or heat
Tendency to corrode

21. 15-2 – Properties of Matter
Physical Changes
Physical changes are changes that do not result in the formation of a new substance.
The substance is still the same because chemical bonds have not been broken or formed, and so the atoms of the molecules are still connected in the same way.

22. 15-2 – Properties of Matter
Chemical Changes
referred to as chemical reactions.
always produce new substances with properties that are typically very different from those of the reactants.
some clues that can indicate a chemical change has occurred.
visible flames
color change
bubbling or fizzing
smoke
heat or light given off
formation of a substance in a different state (for example, a solid from two liquids)
Of these observations, seeing flames is the only sign that always indicates a chemical change. All of the others can sometimes be the result of a physical change.

23. A tree burns to form ashes
Event
Physical
Chemical
Cutting your hair
Mixing sugar and water
Baking soda reacts with baking soda and forms a gas
A piece of paper is crumpled up
Baking cookies
An aspirin is crushed into a powder
A tree burns to form ashes
Methanol is burned and leaves a residue
Water freezes to ice
A piece of metal is bent in half

24. 15-2 – Properties of Matter
Law of Conservation of Mass
Mass cannot be created or destroyed
To put the law another way, the amount of matter before the change equals the amount of matter after the change.

25. 15-2 – Properties of Matter
The law of conservation of mass is also true for physical changes. An ice cube has the same mass as the water produced when it melts.
In other cases, conservation of mass is less obvious. If we think about it, we can usually explain cases in which the law of conservation of mass seems to have been violated.