Electrons and Chemical Bonding
1. Proton = positive, Neutron = neutral, Electron = negative
2. Silicon
3. Columns = oxidation number or valence number, Rows = electron energy level or shell
4. Chemical bonding is the exchange or sharing or electrons to make a fill the outermost energy level with electrons.
5. Lose electron = 1+, gains electron = 1-
6. Ionic bonding is transfer of electrons; covalent bonding is sharing of electrons.
7. Valence electrons are the number of electrons in the outermost energy level ranging from 1 to 8. These are the electrons that are directly involved with chemical bonding.
8. Na has 1 valence electron
9. Mg would bond with any element in column 16 starting with oxygen, sulfur, selenium, etc.
10. An ion is a positively or negatively charged atom because it has either lost or gained an electron respectively.
11. Oxygen ion charge is 2-, Sodium ion charge is 1+
12. All atoms want a full outer shell of 8, except H and He who want 2 to full their outer shell.
13. Oxygen Carbon Neon
Chemical Reactions
1. A chemical reaction is the process by which one or more substances change to produce one or more different substances.
2. Hydrogen gas plus oxygen gas when lit with a match with explode and become water.
3. Four signs of a chemical reaction are: gas released, color change, formation of a precipitate, energy change.
4. During a chemical reaction, bonds break, atoms rearrange, new bonds form.
5. Reactant = starting substance in a reaction, Product = Final substance after atoms have been rearranged and bonded.
6. A chemical formula is a combination of symbols and numbers that represent one substance
7. Law of conservation of Mass = Mass cannot be created nor destroyed in a reaction.
8. Pb(OH)2 = 1 Pb, 2 O, 2 H Al2(SO4)3 = 2 Al, 3 S, 12 O
9. Zn + 2HCl yields ZnCl2 + H2
10. Ionic Bond
11. Covalent Bond
12. The “sea of electrons” is when the electrons are free to flow in and out of the metal nuclei allowing electricity to move in a current down the metal. The electrons are not stuck to a single nuclei, but can move freely throughout the entire metal.
13. Synthesis, Decomposition, Replacement, Combustion
Energy and Rates of Reaction
1. Law of conservation of energy = energy cannot be created nor destroyed it can only be transformed.
2. Activation energy = the amount of energy required to get the reaction started so the reactants can become the products. Without enough activation energy the reaction will not progress forward.
3. Surface area, temperature, concentration, presence of an inhibitor or catalyst.
4. Temp increase = faster reaction, temp decrease = slower reaction
Concentration increase = faster reaction, concentration decrease = slower reaction
Surface area increase = faster reaction, surface area decrease = slower reaction
Catalyst increase = faster reaction, catalyst decrease = slower reaction
Inhibitor increase = slower reaction, inhibitor decrease = faster reaction.
5. Inhibitor = slows or stops a reaction from progressing forward, Catalyst = lowers the activation energy of a reaction so the reaction can progress forward more quickly.
6. Exothermic = energy is released and the products end with less energy then the reactants started with.
7. See 4.4 directed reading number 11
8. Endothermic = energy is absorbed and the products end with more energy than the reactants started with.
9. See 4.4 directed reading number 11.
Chapter 3: Acids/Bases
1. Sour taste, range from 0-6.9 pH, increase H+ ions, react with metals to form hydrogen gas, conduct electricity
2. Bitter taste, slippery, range from 7.1 to 14, increase OH- ions, detergents, conduct electricity.
3. Acid
4. Base
5. 0-3
6. 7.1-11
7. Neutralization is combining a strong acid and a strong base, which will neutralize each other and create neutral end products. The OH- ions from the base react with the H+ ions from the acid.
8. H2O and Salt
Chapter 4: Atomic Energy
1. Alpha releases large alpha particles known as helium and energy, beta releases small electron particles and energy, gamma releases waves of energy only known as gamma rays.
2. Alpha can be stopped by skin, paper, cloth, beta can be stopped by thick aluminum, and gamma needs inches of lead or meters of concrete.
3. Radioactivity is the breakdown of an unstable nucleus releasing particles and a lot of energy.
4. An isotope is an element with the same number or protons, but a different number of neutrons. Carbon 12 and Carbon 14.
5. Alpha particle is 2 protons and 2 neutrons (helium)
6. Beta particle is an electron or a positron.
7. 40 grams at 200 years, at 400 years 20 grams remain; at 600 years 10 grams remain.
8. Fission is the splitting of the nucleus of an atom at room temperature.
9. Fusion is the combining of the nucleus of two atoms at high temperatures, like that of the sun.