1. Chemistry of Life: Nature of Matter and Water
Honors Biology

2. The Nature of Matter positive 1 nucleus no charge 1 nucleus electrons
I. Atom: smallest unit of matter
A. Subatomic Particles
Particle
Charge
Relative Mass
Location in Atom
proton
neutron
negative
positive 1
nucleus
no charge 1
nucleus
electrons ~0
Outside nucleus
Most atoms are neutral because they have equal numbers of
protons and electrons.
Atoms that lose electrons have a positive charge.
Atoms that gain electrons have a negative charge.

3. Draw the following picture of a Carbon atom:
Neutral Atom of Carbon:
Protons(+)
Neutrons
Electrons(-)

4. Draw the following picture of a Carbon atom:
Positive Atom of Carbon:
Negative Atom of Carbon:
Neutrons
Electrons(-)
Protons(+)

5. II. Element: substance made of one type of atom
The Nature of Matter
II. Element: substance made of one type of atom
A. atomic number: #protons: defines an element (also # of electrons in a neutral atom)
B. mass number: sum of protons + neutrons in an atom
How many neutrons in a Sodium atom? 12

6. Isotopes:
C. isotope: atoms of the same element with different numbers of neutrons
D. radioactive isotope: isotope with an unstable nucleus that breaks down over time (emits radiation)
uses: dating fossils, diagnosing and treating diseases, killing bacteria in food/ on surgical equipment
Nonradioactive carbon-12
Nonradioactive carbon-13
Radioactive carbon-14
6 electrons
6 protons
6 neutrons
8 neutrons
7 neutrons

7. How to read the periodic table

8. The Nature of Matter
III. Compound: substance formed by the chemical combo of ≥ 2 elements in definite proportions (ex. NH3, NaCl)
IV. Chemical Bonds
ion: atom that’s gained or lost electrons
1. ionic bond: bond formed by transfer of electrons from one atom to another

9. The Nature of Matter Sodium atom (Na) Chlorine atom (Cl) Transfer
of electron
Protons +11
Electrons -11
Charge
Protons +17
Electrons -17

10. The Nature of Matter Transfer of electron Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na+)
Chloride ion (Cl-)
Transfer
of electron
Protons +11
Electrons -11
Charge
Protons +17
Electrons -17
Electrons -10
Charge
Electrons -18
Charge

11. Nature of Matter
2. covalent bond: bond formed when atoms share electrons
molecule: group of atoms covalently bonded together

12. Van der Waals Forces
A slight attraction that develops between the oppositely charged regions of nearby molecules.
Example: Newt walking up glass window

13. Properties of Water 10 10 Oyxgen Atomic # : 8 Hydrogen Atomic #: 1
# of Protons:
# of electrons:
Overall charge: 10 10

14. Water: Needed for Life
Water has several properties that make it necessary for life.
It is POLAR - has area with a slight
+ charge, and an area with a slight - charge.

15. Why is water polar?:

16. Water: Needed for Life
Hydrogen Bonding: attractive force between hydrogen and another electronegative atom in a different molecule

17. Water: Needed for Life
Hydrogen Bonding allows one H2O molecule to “stick” to another H2O molecule.

18. Cohesion ability for water molecules to stick to themselves
Water: Cohesion
Cohesion ability for water molecules to stick to themselves
Surface Tension
Beads of Water

19. Water: Adhesion
Adhesion ability for H2O molecules to stick to other materials
Meniscus in a graduated cylinder

20. Water: Adhesion and cohesion allows capillary action

21. A solvent has the ability to dissolve other materials
Water: A Great Solvent
Remember…
A solvent has the ability to dissolve other materials
Water is a solvent for many things
For example: The liquid part of your blood (the plasma) is 90% water
Some items, such as fats and oils DO NOT dissolve in water.

22. Mixture:
Combo of 2 or more substances that are physically mixed but not chemically combined!!
Examples: soil, salsa, trail mix, jello, sugar water.

23. Types of Mixtures: A. Solution: one substance dissolves in another
Won’t separate over time
Can’t be filtered
Light passes through cleanly
Homogenous: uniform, evenly distributed

24. Parts of a Solution : a. Solute:substance that is dissolved
b. Solvent:substance that does the dissolving.

25. Kool-Aid
Solution
Solute:
Kool-Aid powder
Solvent:
Water

26. B. Suspension: mixture of liquid and non-dissolved materials
Particles are bigger, visible with naked eye
“murky” or “opaque”
Particles will settle out
Can be separated by filtration

27. Suspension Heterogenous: not evenly distributed
Examples: sand in water, Italian
Salad dressing, paint, liquid
medicines that requires shaking before being taken

28. C. Colloid
Homogeneous
Smaller particles than suspension but bigger than molecules in solution
won’t settle out, can’t be separated by filtration
scatters light
Can’t see materials with naked eye
mayonnaise, milk, blood, aerosols, smog, Shampoo, gels

29. Now test what you learned:
Indicate whether each mixture each is a solution, suspension or colloid

30. The pH scale is used to measure the strength of acids and bases
pH: What is it?
The pH scale is used to measure the strength of acids and bases

31. Some properties of acids and bases
pH: What is it?
Some properties of acids and bases pH
Example
Characteristics
Acids
Neutral
Bases
Lemon vinegar soda, aspirin
Sour, burns, dissolves things
< 7
Pure Water
------
= 7
Soap,
baking soda, ammonia
> 7
Bitter, Slippery

32. H2O H+ + OH-   pH: What is it?
Some compounds break up into ions when they dissolve in water.
Solutions with more H+ ions are more ACIDIC
They have a LOW pH (<7)
Solutions with less H+ ions are more BASIC
They have a HIGH pH (>7) 
H2O H OH- 

34. pH: Looking at common items
Battery Acid
pH = 0
Orange Juice
pH = 3
Ocean Water
pH = 8
Oven Cleaner
pH = 13

35. pH: Importance to Humans
Blood has a pH of 7.4 (about neutral)
If pH goes below 6.8 or above 7.8 it is deadly!
To keep blood at the proper pH - our body uses buffers

36. pH: Buffers
Buffers are weak acids and bases that neutralize, or weaken, strong acids or bases.
In blood, buffers prevent pH change.
Sodium bicarbonate, or baking soda, is a buffer