1. Chemistry

2. Atoms
The smallest particle into which an element can be divided and still be the same substance
All living things are made of atoms

3. Subatomic Particles Protons: Positively charged Located in the nucleus
Neutrons:
No charge (neutral)
Electrons:
Negatively charged
Located in the electron cloud (orbitals)

4. Electron Configuration
The location within the electron cloud where the electrons are most likely to be found
1st shell holds maximum of 2 electrons
All other shells hold a maximum of 8 electrons

5. Atomic Structure

6. Periodic Table

7. Elements on the Periodic Table
Atomic Number = Protons = Electrons
Atomic Weight = Protons +Neutrons

8. How to find numbers of… Number of protons = Atomic Number
Number of electrons = Atomic Number
Number of neutrons = Atomic Weight – Atomic Number
*Round atomic weight to the nearest whole number before subtracting

9. Valance Electrons The number of electrons in the outer shell.
Used for bonding

10. Octet Rule
When bonding, each atom wants to have a full outer shell (8 valance electrons)
***Exception is Hydrogen, which can only hold two electrons in its outer shell

11. Bonding to Make Compounds

12. Compound
A substance made of two or more atoms that bond together using their valance electrons
Ex: H2O, CO2

13. Types of Bonds
Ionic Bond
Covalent Bond
Hydrogen Bond

14. Ionic Bonds
When bonds form between atoms by either gaining or losing electrons
Results in the atom having either a positive or negative charge which is attracted to the other atom in the molecule

15. Ions When an atom has an electrical charge it is called an ion
If an atom gains an electron it has a negative charge
If an atom loses an electron it has a positive charge

16. Covalent Bonds
When bonds form between atoms by sharing valence electrons

17. Polarity
When shared electrons are attracted to one atom more strongly than another, so it has a slightly negative charge
The other atom that the electrons are less strongly attracted to has a slightly positive charge

18. Hydrogen Bond
When a hydrogen atom has a partial positive charge that attracts to the negative end of specific other molecules such as oxygen, nitrogen, and fluorine
Often observed in water
This is a relatively weak bond, but it allows water to have some special properties

19. Chemical Reaction
The process of rearranging the bonds within two or more substances in order to form at least one new substance

20. 6CO2 +6H20  C6H12O6 + 6O2
The number before the compound tells you how many there are of each compound
Atomic symbols tell what elements are in the compound
Subscripts tell how many of each element are in the compound
***Must have an equal number of each element on both sides of the reaction

21. Reactants
A substance that is present at the beginning of a chemical reaction

22. Products
A substance that is formed during a chemical reaction

23. Conservation of Mass
Matter cannot be created or destroyed, only rearranged