1. Intro to Chemistry

2. All matter is made of __________
atoms
Non-Living
Living

3. Atoms
Atom: Smallest particle of an element that retains the characteristics of that element.
Element: The simplest chemical substance
Arranged in the periodic table
Columns and rows
Each element is identified via 1 letter or 2 letter abbreviation

6. Diagram of an Atom

7. Structure of an Atom Surrounded by Electrons (e-)
Travel in regions called energy levels (shells)
2 in 1st shell
8 in 2nd shell
8 in 3rd shell

8. Review What is “anything that takes up space and has mass” called?
Which is smaller: a cell or a molecule?
What are the three parts of an atom?
Which part of an atom (subatomic particle) has a negative charge?
What charge does a neutron have?
What two subatomic particles are in the “nucleus” of the atom?

9. Nice.

11. Periodic Table Crash Course
Columns go up and down
Rows go left and right
Metals are left of the zigzag, Nonmetals to the right (except H)
Elements are uncharged, which means the number of protons MUST EQUAL the number of electrons
Column numbers tell you valence shell electron number
Valence shell electrons: The outermost electrons on an atom.

12. We measure an atom’s size in two ways: The atomic number
As you add electrons, protons, and neutrons, the size of the atom increases.
We measure an atom’s size in two ways:
The atomic number
The atomic mass
Honors

13. How Many Protons in An Atom?
The atomic number is the number of protons in an atom.
Honors

14. What is the name of the atom with 12 protons?
How many protons does oxygen have?

15. If I stole a proton from Carbon, what would happen?
If the number of protons in an atom changes, the atom changes.
So…..
If I stole a proton from Carbon, what would happen?
If I gave an extra proton to Carbon, what would happen?
Honors

16. The atomic mass is approximately the number of protons + neutrons.
To find the # of neutrons, solve for N:
AM = N + P
So N = AM – P
Honors

17. How Many Neutrons in An Atom?
Round the atomic weight to the nearest whole number.
This is approximately the number of protons + number of neutrons
2. Subtract the number of protons (atomic number) from the rounded atomic weight.
Ex: What is the atomic weight of Krypton (number 36)?
83.80
83.80  84
How many neutrons are in Krypton?
84 – 36 =
48!
Honors

18. These atoms are called ions.
How Many Electrons in An Atom?
A stable atom has as many electrons as it does protons.
If the number of electrons in an atom changes, the atom becomes unstable. It will become electrically charged, and will readily react with other atoms.
These atoms are called ions.
Two atoms are walking down the street when one of them says “oh no, I think I lost an electron” the other one replies “are you positive?”

19. When an atom loses an electron, it becomes positively charged.
When an atom gains an electron, the atom becomes negatively charged. H-
(a negatively
charged hydrogen ion) H+
(a positively
charged hydrogen ion)
H (neutral)
Honors

20. Covalent Bond: a bond formed by sharing one or more pairs of electrons.
Ionic Bond: a bond between oppositely charged atoms, formed when one or more electrons are passed from one atom to another.
Hydrogen Bond: a weak bond formed between hydrogen and an atom with a negative charge.
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21. Single and Double Covalent Bonds
Single Covalent Bond
If two atoms each share 1 electron (for a total of 2 shared electrons), a single covalent bond is formed.
Represented by a single line –
Double Covalent Bond
If two atoms each share 2 electrons (for a total of 4 shared electrons), a double covalent bond is formed.
Represented by a double line =
Stronger and more rigid than a single bond.

22. Mixtures vs. Solutions
Mixture: A combination of substances where both substances keep their original properties.
Physically mixed, not chemically mixed.
Solution: One or more substances (solutes) are distributed evenly in another substance (solvent)
The more solute in a solvent, the higher the concentration.
Suspensions: Mixtures of water and non dissolved particles
Example: Blood

24. pH Scale
pH: a measure of how acidic or basic something is (pH: power of Hydrogen)
pH 0-6: Acid
Acids form H+ ions in water
Example: Lemon (pH=2)‏
pH 7: Neutral
Example: Pure water and blood‏
pH 8-14: Base
Bases form OH- ions in water
Example: Ammonia (pH=12)‏

25. pH Scale
pH: a measure of how acidic or basic something is (pH: power of Hydrogen)
pH 0-6: Acid
Acids form H+ ions in water
Example: Lemon (pH=2)‏
pH 7: Neutral
Example: Pure water and blood‏
pH 8-14: Base
Bases form OH- ions in water
Example: Ammonia (pH=12)‏

26. pH Scale

27. Elements of Life