1. BASIC CHEMISTRY FOR UNDERSTANDING BIOLOGY

2. Basic Terms Atom – the smallest component of matter Proton (+)
Neutron (neutral)
Electron (-)

3. Elements 96% of all living things made of 4 elements:
Element – pure substance composed of one type of atom
96% of all living things made of 4 elements:
Oxygen (65%)
Carbon (18.5%)
Hydrogen (9.5%)
Nitrogen (3%).

5. Reading the Periodic Table

6. Remember this!!!! Atomic number = # of protons
Atomic mass= #protons + # neutrons
Neutrons= atomic mass - # protons
The ATOMIC # determines what element the atom is. This stays constant.

7. Analyzing an element Element? Atomic Mass? Atomic Number? How many?
Protons
Neutrons
Electrons

8. Electron configuration
Shells, orbitals, energy levels
1st : 2 e-
2nd : 8e-
3rd : 18e- *(temporarily stable w/ 8)
4th : 32e-

9. Electron Configuration

10. Terms to know
Isotopes, ions, new elements

11. Isotope
Same number of protons in atom, but different # of neutrons

12. Reactivity
A partly-filled energy level makes some atoms chemically reactive—wants to fill their highest energy levels.

13. Bonds

14. Ionic bonds - formed by the attraction between two oppositely charged ions. (Ex: NaCl)
*electrons are completely transferred from one atom to another

15. Ionic Bonds

16. Covalent Bonds sharing of electron pairs between atoms, strong (Ex: CH4)

18. Hydrogen Bonds Attractive interaction of a hydrogen atom with an electronegative atom, fairly weak

19. Water ¾ earth covered in H20 66% of human body (+) (-)
*Polar molecule: Doesn’t share the electrons evenly
(+)

20. Hydrogen bonds (weak) H2O molecules are attracted to each other
Gives water its unique characteristics

21. SOLUTE is what’s being dissolved in SOLVENT. This forms a SOLUTION.
Best SOLVENT on Earth…..meaning it will dissolve more compounds than any other liquid
SOLUTE is what’s being dissolved in SOLVENT. This forms a SOLUTION.
SOLUTE
SOLVENT

22. Water as a solvent Dissolves ionic compounds especially well
Water molecules surround and separate positive and negative ions

23. Boil H2O  molecules motion  break bonds
Freeze H2O  molecules motion  spaced apart in
fixed crystal formation
Solid ICE EXPANDS and is LESS dense than water! Weird.

25. Cohesion
When water molecules are attracted to each other (attraction between like-substances)
“Dome shape” of a drop. Molecules on surface are holding each other tight, creating surface tension

26. Helps insects walk across water
Cohesion …
Helps insects walk across water

27. Adhesion Attraction between UN-LIKE substances (water to side of tube)
Capillary action-water molecules will “climb”, pulling each other up a thin tube
Capillary action; combo of cohesion/adhesion 1

29. Transpiration is like capillary action in plants
Transpiration is like capillary action in plants. process which plants/trees remove water from the soil

30. High heat capacity
Water can absorb a lot of heat energy before it raises temperature
When does Lake Michigan temp become tolerable?
Thank you!

31. Properties of Water : pH
Water itself is partly ionized
H2O    H+ + OH-
pH Scale 1-14
Acidic pH = 1-6
More H+ ions
Neutral pH = 7
Basic pH = 8-14
Bases accept H+ ions, lots of OH-