1. Earth Science Learning Plan 2 Ch. 2—Chemistry
Mr. Aprill
Revised: 11/19/13

2. The Atom
An atom is the smallest particle of an element that still has all the properties of that element.
118 Known elements (As of Nov. 2011)
98 occur naturally.

3. Models of Structure Nucleus (+ charge) Electron Shell (- Charge)
Protons (+)
Neutrons (NO CHARGE)
Electron Shell (- Charge)
Electrons (-)
In a neutral Atom p = e

4. Mass # & Atomic # Mass Number: protons + neutrons
m = p + n
Atomic Number = protons
What’s the atomic number & mass number of the following elements?
Ex. Iron
Iron 26 Fe
55.847
Helium 2 He
4.003
Hydrogen 1 H
1.0080
Ex. Helium
Ex. Hydrogen
What are some ways to remember which number is the mass number and which is the atomic number?

5. Neutral Atoms
In neutral atoms, the electrons are always equal to the protons.
What is a way to remember the number of electrons?
In a neutral atom, the electrons must equal the protons to have a net neutral charge.
How many electrons does each have?
Chlorine 17 Cl
35.453
Zinc 30 Zn
65.37
Uranium 92 U
238.03

6. Isotope
Atoms of the same element that have different number of neutrons.
What would happen if you changed the number of protons?
Sulfur—32 vs. Sulfur—36
Sulfur 16 S
32.064
Argon—36 vs. Argon—38 Ar 18
39.948

7. Ions Electrically charged atoms
Chlorine 17 Cl
35.453
Ions
Electrically charged atoms
What happens to the electrons in order for the atoms to become charged?
gain or lose electrons
Anions (Negatively charged atoms)
Cations (Positively charged atoms)
Sodium 11 Na
22.990
Beryllium 4 Be
9.012
Determine if a anion or cation & number of protons & electrons.
Cl- Na Be Se-2
Selenium 34 Se
78.96

8. Types of Chemical Bonds
Ionic
Charged ions with opposite charges
Generally: Metals & Non-metals
An IONIC BOND is the result of the transfer of one or more electrons from a metal onto a non-metal.
Example: Sodium Chloride (NaCl)

9. Types of Bonds Covalent Bonds (Single, Double, Triple)
Bonding between non-metals
COVALENT BONDS involve Sharing electrons

10. Types of Bonds H20 (Single Covalent) O2 (Double Covalent)
N2 (Triple Covalent)

11. Let’s see what happens when you break the bonds apart.
Gummy Bear Demo
What do we know?
C6H12O6 (Double Covalent)
1 Serving = 17 gummy bears OR 140 calories
Record observations: sound, sight, smell

12. States of Matter
Solid: definite shape and volume. Particles are in a fixed position relative to each other.
Liquid: particles are not in fixed positions. The added energy allows them to move around and change positions.
Gases: particles can move freely and independently. Gases fill a container.
Plasma: Most common state of matter. Stars (ie sun), magnetic field of Jupiter, Lightning bolts.

13. Energy From Atoms
Where does energy in the U.S. come from?

14. Energy in the U.S. Mostly from fossil fuels (85%) Nuclear (8%)
Petroleum (40%)
Coal (22%)
Natural Gas (23%)
Nuclear (8%)
Renewable Energy (7%)
Hydroelectric (4%)

15. Compounds
Compounds: contain atoms of more than one type of element that are chemically bonded together.
Examples: Water (H2O), Table Salt (NaCl)

16. Mixtures
A mixture is: composed to 2 or more substances that are NOT chemically combined.
2 Types:
Heterogenous Mixture: Not mixed evenly, each component retains its own properties.
Homogeneous Mixture (Solution): evenly mixed, can’t see individual components.

17. Chemical Properties
Describes: a change that occurs when one substance reacts with another substance.
Examples: Iron reacting with oxygen and water, forming iron oxide (rust).
Electricity passed through water, separates water into H and O.
Calcium reacting with acid and fizzing.

18. Physical Properties
Properties that you can observe without changing a substance into a new substance.
Examples:
Color
Density
Solid, Liquid, Gas (State of Matter)
Freezing/Melting Point
Magnetic