1. Review for Bonding Test

2. Bohr Diagrams L K M N “K” holds 2 e- “L” holds 8 e- “M” holds 18 e- “N” holds 32 e- The farther away from the nucleus, the more energy the electrons have. Those on the outer- most energy level are the valence electrons used in bonding.

3. Draw a Bohr Diagram of Oxygen Oxygen has an atomic number of 8.

4. How many electrons are needed in the outer energy levels for an atom to be chemically stable? Eight (Octet Rule) If an atom has 15 electrons, how many valence electrons does it have? 5

5. C 14 (C)has how many neutrons? 14 because the 14 is telling you that it is an isotope and has more neutrons than protons. Li 7 (Li) has what mass number? Lithium has 3 as it’s atomic number, therefore it has 3 protons. Add the 7 neutrons from this isotope and the mass number is 10 amu.

6. Compounds that contain carbon and were once living are known as…? Organic Family # 17 is known as the “Salt- Producing” elements. What are they? Halogens

7. Where are the lightest (lowest mass) elements located on the periodic table, Left or Right side? Left side Which is the lightest of all the elements? Hydrogen (H) What is the molecular mass of water (H 2 O)? H = 1, O =16………1 + 1 + 16 = 18 amu.

8. What is the difference between a molecule and a compound? A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements. All compounds are molecules but not all molecules are compounds. Which of these is a compound? He, HCl, H 2 O, H 2, N 2 HCl and H 2 O

9. How many different elements are in the compound sodium carbonate (Na 2 CO 3 )? 3; Na, C and O How many atoms does the above compound have? 6

10. Lewis Dot Diagrams show what part of an element? Valence electrons only. What does the following Lewis Dot structure show? Carbon is sharing 4 SETS of electrons with Oxygen and they all are now stable with 8 valence electrons each.

11. A chemical bond that occurs when atoms share electrons is a(n) _______ bond. Covalent Bond Covalent Bonds occur between what two types of elements? Non-Metals Non-metals are located where on the Periodic table? To the right of the stair-step metalloids (B, S, G, A, S, T, P, A). Exception - Hydrogen

12. What kind of chemical bond occurs when an equal exchange of electrons occurs? Ionic Bond What is the name for losers of electrons that form positive ions? Cations What is the name for gainers of electrons that form negative ions? Anions

13. Ionic bonds occur between which two types of elements? A metal and a non-metal Which type of elements are UNLIKELY to form bonds? Noble Gases How can you quickly determine if a Lewis Dot Structure is showing an Ionic bond? It is between a metal and a non-metal and it will show a sign (+ or -)

14. How do you name an ionic bond between a metal and a non-metal? Metal comes first (leave name the same) Nonmetal second (Use “ide” ending) How do you name a covalent bond between two non-metals? Put Greek prefixes in front of the elements names to tell how many atoms there are. What are the names of the following? NaCl, CO, CO 2 and N 2 O 4 Sodium Chloride, Carbon Monoxide, Carbon Dioxide and Dinitrogen Tetroxide

15. What are the Greek Prefixes for the following? 1 thru 10 1- Mono 2- Di 3-Tri 4- Tetra 5- Penta 6- Hexa 7- Hepta 8- Octa 9- Nona 10- Deca

16. What does this cartoon mean?