1. Chemical Bonding

2. Compounds Compound: two or more elements bonded together chemically
Compounds have different properties than their individual parts

3. Formulas
Chemical formula: tells what elements a compound contains and the exact number of the atoms of each element in the compound
Examples:
NaCl = 1 sodium and 1 chlorine
H₂O = 2 hydrogen and 1 oxygen
C₆H₁₂O₆ = 6 carbon, 12 hydrogen and 6 oxygen

4. Atomic Stability
Atomic Stability: Atoms with a full outer energy level are more stable
Atoms form compounds to gain stability by losing, gaining or sharing electrons

6. Chemical bonds
Chemical bonds: the force that holds atoms together in a compound

7. Ions Ion: an atom that has gained or lost an electron
Becomes a charged particle because it has either more or fewer electrons than protons
Example: Elements in groups 1 and 17 form ions easily
Na⁺
Cl⁻

8. Ions Iodine: “Wanted: one electron to borrow”
Potassium: “Available: one electron to lend”

9. Ionic bonds Ionic bond: when electrons are gained or lost
Caused by the attraction of opposite forces
Results in a compound with a neutral charge

10. Covalent bonds
Covalent bond: when electrons are shared between 2 atoms
Molecule: a neutral compound that is formed during covalent bonding

11. Covalent bonds Single covalent bonds: made up of 2 shared electrons
Example: water H₂O, ammonia NH₃, Sulfur Dioxide SO₂

12. Covalent bonds
Multiple covalent bonds: contains more than one pair of electrons being shared
Example: atmospheric nitrogen: N₂

13. Sharing of Electrons
Unequal Sharing of electrons: sometimes the electron spends more time around one of the elements in the compound
Polar molecule: a molecule that is slightly positive on one end and slightly negative on the other end because of unequal sharing of electrons
Example: water

14. Polar vs non-polar
Nonpolar molecule: a molecule in which electrons are shared equally
Example: methane CH₄ ,Hydrogen H₂, chlorine Cl₂, Carbon dioxide CO

15. Formulas Binary compound: a compound that is composed of two elements
Example:
potassium iodide = KI, carbon monoxide = CO
Oxidation numbers: the number of electrons an atom has gained or lost in order to become stable
Examples:
Sodium ion = Na⁺¹
Chloride ion = Cl⁻¹

16. Formulas
Polyatomic ion: a positively or negatively charged, covalently bonded group of atoms
Example:
Baking soda: hydrogen carbonate = HCO⁻₃

17. Hydrates Hydrate: a compound that has water chemically attached to it
Example:
cobalt chloride hexahydrate
CoCl₂ + 6 H₂O

18. Prefixes Prefixes: used when naming binary covalent compounds Example:
NO = nitrogen oxide
NO₂ = nitrogen dioxide
N₂O = dinitrogen oxide

19. Chemical Reactions
Chemical Reaction: a change where one or more substances are converted into new substances
Reactants: the substances that react
Products: the new substances produced

20. Conservation of Mass
Conservation of Mass: Mass cannot be created or destroyed
The mass of the reactants ALWAYS equals the mass of the products

21. Father of Chemistry
Antoine Lavoisier: explained the conservation of mass
Described what was happening in combustion reactions
Experimented on cellular respiration and metabolism

22. Chemistry Nomenclature: the science of naming things
Chemical Equation: a way to describe a chemical reaction using chemical formulas and other symbols
NiCl₂(aq) + 2NaOH(aq)  Ni(OH)₂(s) + 2NaCl(aq)

23. Chemistry symbols  produces + plus (s) solid (l) liquid (g) gas
(aq) aqueous (dissolved in water)
Heat
 reactants are heated
Elec.
 electric current is applied to reactants
Light
 reactants are exposed to light