1. Chemistry
Chapters 2 and 3

2. Ex: Number of e-s or neutrons
Properties of Matter
Physical – observed and measured without permanently changing identity of matter
Ex: mass and volume
Chemical – describe a substance’s ability to change into a new substance (i.e., chemical change)
Ex: Number of e-s or neutrons

3. Phases of Matter (physical properties)
Gas
Liquid
Solid

4. Composition of matter
Atoms – smallest structures of matter that are unable to be broken down further and maintain their properties
Protons: + ; weigh 1 AMU
Neutrons: 0 ; weigh 1 AMU
Electrons: – ; weigh 1/1836 AMU
E levels differ with number of electrons present

5. Atomic number and mass The atomic number is … The atomic mass # is …
# of protons in atom
The atomic mass # is …
# of protons AND neutrons

6. Chemical elements
Over 100 elements (90 found in nature; the rest have been created in the lab)
Isotopes – atoms with extra neutrons. What does that mean for the atom? How can you determine if an element is an isotope?
Ion – atom or molecule with + or – e-s

7. Electrons e-s are found in E levels or shells More E = higher E level
Less E = lower E level
Valence = outer E level
Octet rule – atoms like having 8 e-s in their valence shell (2 for H)

8. Interactions of Matter
In order to achieve stability, an atom will either gain, lose, or share e-s, which will change the physical and chemical characteristics
Ionic Bonds – transfer of e-s

9. Interactions of Matter
Covalent Bonds – sharing e-s; can be single, double, or triple bonds

10. Interactions of Matter
Polar Covalent Bonds – unequal sharing of e-s

11. Interactions of Matter
H-bonds and Van der Waals – interaction between slight charges

12. Water
The most important property of the water molecule is that it is slightly charged on each end due to an uneven distribution of e-s + -

13. Water Cohesion – force attracting water molecules to each other.
Causes surface tension, which is why this lizard can “run” on water

14. Water
Adhesion – water molecules attracted to other slightly charged molecules
Capillarity – combination of the other two forces which causes the movement of water upward through tube cells
Transpiration pull

15. Water
A solution is a substance that is uniformly spread throughout; with or without a chemical change.
Solvent – substance that does the dissolving
Solute – what is to be dissolved
Examples:
Sugar and water
Tea, coffee

16. Example of Importance to Life
Properties of Water
Property
Example of Importance to Life
Cohesion
Water flows, forming habitats and a matrix for biological molecules
High (specific) heat capacity (1g, 1OC)
Water regulates constant internal body temperature
High heat of vaporization (1g to gas)
Evaporation (evaporative cooling – sweating)
Adhesion
Water acts as a solvent
Solid less dense than liquid
Keeps ponds and lakes liquid

17. Dissociation of Water
Water can dissociate into the hydrogen and hydroxide ions
H2O  H+ + OH-

18. Water
Acids – Compounds that release H+ ions (much like how NaCl dissociates in water but H+ are one of the most reactive ions on the planet)
Bases – Compounds that release OH- (is the opposite of an acid; the OH- are as reactive as H+)
Combining an acid and a base produces water and a salt

19. The more H+ present, the lower the pH #
The more OH- present the higher the pH #