1. The Science of Chemistry
Chapter 1
The Science of Chemistry

2. SCIENCE Latin having knowledge
Study concerned with the observation and classification of facts
examples:

3. SCIENTIST
Search for relationships that can be used to explain and predict the behavior of things
HOW???
EXPERIMENT

4. CHEMISTRY
A Laboratory science that deals with the composition, structure and properties substances and the changes they undergo

5. Section 1-1 What is Chemistry?
Objectives:
Describe the characteristics of the three most common physical states
Draw models to represent solids, liquids & gases
Write a word equation for a chemical reaction
Identify the reactants and products in a chemical reaction
Distinguish between exothermic and endothermic reactions

6. Describe the characteristics of the three most common physical states
A… States of Matter
B… Kinetic Molecular Theory

7. Physical States solid liquid gas fixed volume and shape fixed volume
Sodium
Mercury
Silicon
Nitrogen
Neon
solid
fixed volume and shape
liquid
fixed volume
shape of container, horizontal top surface
gas
takes shape and volume of container

8. The Big Three: Water
S,L,G
Solid Liquid Gas

9. B. Kinetic Molecular Theory
KMT
Particles of matter are always in motion.
The kinetic energy (speed) of these particles increases as temperature increases.

10. B. Four States of Matter Solids
very low KE - particles vibrate but can’t move around
fixed shape
fixed volume

11. B. Four States of Matter Liquids
low KE - particles can move around but are still close together
variable shape
fixed volume

12. B. Four States of Matter Gases
high KE - particles can separate and move throughout container
variable shape
variable volume

13. B. Four States of Matter Plasma
very high KE - particles collide with enough energy to break into charged particles (+/-)
gas-like, variable shape & volume
stars, fluorescent light bulbs, CRTs

14. The Big Three
States of matter demo

15. The Big Three
#8 States of Matter
Gas Liquid Solid

16. 3 States of Bromine
Solid
Bromine
Liquid
Vapor

17. Draw models to represent solids, liquids & gases

18. Solid

19. Kinetic Molecular Theory: Solid
particles are tightly packed together in regular array
particles vibrate about average positions
seldom squeeze past other atoms
results in a rigid material with a small, fixed volume for a given mass
external shape often reflects internal arrangement of particles

20. Liquid

21. Kinetic Molecular Theory: Liquid
particles are arranged more randomly than in solid
particles less confined so that they can move past one another
particles are a little further apart, thus slightly larger, fixed volume
particles are constantly interacting with one another

22. Gas

23. Kinetic Molecular Theory: Gases
particles in continuous, random, rapid motion
collisions between particles are elastic
volume occupied by the particles is negligibly small effect on their behavior
attractive forces between particles have a negligible effect on their behavior
gases have no fixed volume or shape, take the volume and shape of the container

25. Write a word equation for a chemical reaction
Write a word equation for a chemical reaction. Identify the reactants and products in a chemical reaction

26. Chemical Reactions:
A chemical reaction occurs when two or more chemical substances are mixed together.
This means that the atoms that were joined together in the original substances break apart and rearrange themselves to make a new substance,
one or more substances may be transformed into one or more new substances.
This new substance is quite different from the original substances.

27. Chemical Reactions: Reactant + Reactant ----> Product
Some products of chemical reactions are heat, light, sound and changes in color.

28. Chemical Reactions: Examples of Chemical Reactions:
A sparkler contains magnesium. This, when lit, reacts with oxygen in the air and produces light and heat. 
2Mg + O2  2MgO + Energy
Reactants
Products
Yields

29. Chemical Reactions: Examples of Chemical Reactions:
The chemicals inside a rocket, when lit, react with the oxygen in the air and produce heat, light and sound.
2H2 + O2 2H2O

30. Distinguish between exothermic and endothermic reactions
When chemical reactions occur, as well as the formation of the products, there is also a heat energy change which can often be detected as a temperature change.
This means the products have a different energy content than the original reactants (see the reaction profile diagrams below).

31. Distinguish between exothermic and endothermic reactions

32. Distinguish between exothermic and endothermic reactions
If the products contain less energy than the reactants, heat is released or  given out to the surroundings and the change is called exothermic.
The temperature of the system will be observed to rise in an exothermic change.
Examples:
the burning or combustion of hydrocarbon fuels
the burning of magnesium, reaction of magnesium with acids, or the reaction of sodium with water
the neutralization of acids and alkalis
Thermite reaction

33. Distinguish between exothermic and endothermic reactions
If the products contain more energy than the reactants, heat is taken in or absorbed from the surroundings and the change is called endothermic.
If the change can take place spontaneously, the temperature of the reacting system will fall but, as is more likely, the reactants must be heated to speed up the reaction and provide the absorbed heat.
Examples:
the thermal decomposition of limestone