1. Chemistry Notes

2. Atoms The nucleus of an atom includes: protons and neutrons.
Electrons orbit the nucleus in specific energy levels.
Proton (+)
Electron (-)
Neutron (neutral)

3. Elements
The number of protons never changes – this equals the atomic number. (If the number of protons changes, it is a different element.)
The number of electrons generally equals the number of protons (We won’t worry about exceptions in this class.)
Atomic Number
Atomic Mass

5. Chemical Bonds 3 main types of chemical bonds:
Covalent - atoms share electrons equally
Ionic – one atom hogs the electrons from another (Think of it like a 5-year-old taking a 3-year-old’s toy and hogging it.)

6. Properties of Water

7. Hydrogen and oxygen molecules are covalently bonded, but oxygen holds the electrons closer to itself. This makes the oxygen side slightly negative and the hydrogen side slightly positive – it is POLAR.

8. The positively charged H forms a weak hydrogen bond with the negatively charged O.
These hydrogen bonds lead to the many unique properties of water.

9. Properties of Water
Universal solvent – water can dissolve many types of substances
This allows substances to travel throughout the body.

10. Properties of Water
Cohesion – Water molecules stick to each other – Surface tension

11. Adhesion – Water molecules stick to other surfaces.
This is important, because this is how water travels to the tops of trees and blood flows through your blood vessels.

12. Heat Capacity - It takes a lot of energy (heat) to change the temperature of water (water absorbs heat)
Land near the ocean tends to have mild temperature changes (San Diego)
Heat of Vaporization - Because water takes a lot of energy to heat up, as it evaporates, it takes energy (heat) with it. SWEATING COOLS YOU OFF.

13. Density of Ice - ice is less dense than water, it floats.
Lakes do not freeze solid in the winter, allowing life to survive. The layer of ice on top of the lake insulates the water below so that it doesn’t get any colder than 32°.

14. Acids and Bases
In water, some molecules break apart to create two molecules: H+ (hydrogen ion) and OH- (hydroxide ion). Only about 1 in 10 million molecules do this.
In pure water, the number of H+ and OH- ions is equal, making water neutral.

15. Hydrogen ion concentration [H+] in water equals:
1/10,000,000 = = 1x10-7
-log 1x10-7 removes everything else and gives us only the exponent (power)
-log 1x10-7 = 7
pH = 7
pH = power of Hydrogen

16. pH Scale pH stands for the power of Hydrogen.
The concentration of H+ ions is measured on the pH scale.
The pH scale goes from 0-14.
0 is a strong acid
14 is a strong base 7 is neutral

17. Acid - A solution with a higher concentration of H+ ions is an acid.
Base - A solution with a higher concentration of OH- ions is a base. (Lower H+ concentration.)
(Remember the pH scale goes alphabetically, acids before bases.)

18. A solution that releases H+ ions in water is acidic
A solution that releases H+ ions in water is acidic. (The chemical bonds break and H+ is released.)
A solution that releases OH- ions in water is basic.
Mixing an acid with a base neutralizes them both.
The H+ and OH- combine to form water, the remaining chemicals combine to form salts.
Ex: HCl + NaOH  NaCl + H2O
Ex: HNO3 + KOH 
KNO3 + H2O

19. Practice
Given the pH of each compound, tell if it is acid, base, or neutral:
Blood = 7.5
Soda = 3
bleach = 12
Hair remover = 12.5
Milk = 6.5
Tums = 9

21. Macromolecule Notes

22. Organic Chemistry Organic simply means “Carbon based”
All living things are made up of 4 macromolecules that form the structure and perform the functions for our cells: Lipids Carbohydrates Proteins Nucleic Acids

23. Monomers:
Mono Mere
One -Part
A single building block
Polymers:
Poly
Many
Many building blocks put together

24. Carbohydrates Made up of monomers of monosaccharide
Examples are sugars and starches
Store energy (glucose)
Provide structural support (cellulose)
Made up only of C, H, and O in the ratio: CH2O

25. Lipids
Fats and oils
Store energy more efficiently than carbohydrates (fat)
Provide structure (lipid membrane of cells)

26. Proteins Proteins are long chains of amino acids.
The shape of proteins determine what they do.

27. Proteins (continued)
Transport materials (hemoglobin in blood, transport proteins in cell membrane)
Speed up reactions (enzymes)
Provide structural support (in muscles)
Send signals (hormones)

28. Nucleic Acid Made up of nucleotides
Stores information in the form of DNA or RNA