Unit 5: #7-15

Question 1

7. Describe Dalton, Thomson, Rutherford, and Bohr models of atom. Include experiment.

Answer 1

Dalton: billiard ball model (solid, indivisible spheres)

Thomson: plum pudding / chocolate chip model, tiny movable e- in the dough of diffuse and change

Rutherford: dense and charged nucleus with e- moving around, gold foil experiment

Bohr: specific energy levels (emission spectra)

Question 2

8a. What determines whether an ionic or a covalent bond will form?

Answer 2

The electro negativity between 2 atoms.

Ionic: >1.6
Nonpolar: <0.3
Polar: 0.3<x<1.6

Question 3

8b. How is each bond formed in terms of what happens with the electrons?

Answer 3

Ionic: e- are transferred
Nonpolar: e- are shared equally
Polar: e- are shared unequally

Question 4

8c. What would the following bonds be labeled? (Ionic, Nonpolar, Polar)

i. N-N, ii. N-O, iii. N-Cl, iv. N-Na

Answer 4

i. NPC
ii. PC
iii. NPC
iv. I

Question 5

9. What is the structure and characteristics of ionic and molecular compounds?

Answer 5

Ionic: Crystal lattice of cations and anions, high MP and BP, good conductor, metal and nonmetal

Molecular: individual, low MP and BP, poor conductors, all nonmetal

Question 6

10. Make a Lewis dot diagram for the following atoms. oxygen, nitrogen, lithium, krypton

Answer 6

oxygen-6
nitrogen-5
lithium-1
krypton-8

Question 7

11. Show the formation of the bond of calcium and chlorine.

Answer 7

START: Ca, Cl, Cl
END: Ca2+, Cl-, Cl-

Question 8

12a. Identify the group name, # of protons/electrons,, valence electrons, monoatomic ion charge for neutral atoms. nitrogen

Answer 8

15, 7, 5, 3-

Question 9

12b. Identify the group name, # of protons/electrons,, valence electrons, monoatomic ion charge for neutral atoms. strontium

Answer 9

2 ALKILINE EARTH, 38, 2, 2+

Question 10

12c. Identify the group name, # of protons/electrons,, valence electrons, monoatomic ion charge for neutral atoms. iodine

Answer 10

17 HALOGENS, 53, 7, 1-

Question 11

12d. Identify the group name, # of protons/electrons,, valence electrons, monoatomic ion charge for neutral atoms. helium

Answer 11

18 NOBLE GASES, 2, 2, n/a

Question 12

13. How do you decide how many ions of each type are likely to combine?

Answer 12

As many until neutral compound

Question 13

14. Why is NaCl referred to as sodium chloride, yet use “Tin (IV) Oxide” to describe SnO2? What does the Roman Numeral tell you?

Answer 13

Tin has variable charge and not predictable by the placement on the periodic table, so we specify the charge it has.

Question 14

15a. What is the formula for the compound nitrogen trifluoride

Answer 14

NF3

Question 15

15b. What is the formula for the compound sodium phosphate

Answer 15

Na3 PO4

Question 16

15c. What is the formula for the compound gallium oxide

Answer 16

Ga2 O3

Question 17

15d. What is the formula for the compound iron (III) nitride

Answer 17

FeN

Question 18

15e. What is the formula for the compound hexaboron monosilicide

Answer 18

B6 Si

Question 19

15f. What is the formula for the compound silver sulfide

Answer 19

Ag2 S