Chemistry 100 Dunnivant

Exam 1 Spring, 2007

Name (printed) _____________________

Closed notes, closed book, closed cell phone, closed Internet, closed neighbor!

I have neither given nor received aid on this exam. __________________________

Signature

1. (10 pts) Given the following equation for calculating ^oF, derive (rearrange) an equation for converting from ^oF to ^oC. Show all work. If you simply write the correct formula down you will not receive credit. You must show all algebraic rearrangements.

F = 9/5 C + 32

2. (5 pts) Give two examples of physical changes and two examples of a chemical change. For the chemical change you may use appropriate chemical reactions.

Physical changes: __________________

__________________

Chemical changes: __________________

__________________

3. (10 pts) Name the major categories of electromagnetic radiation. List these from highest to lowest energy and label which end of the spectrum has high versus low frequency and high versus low wavelength. Beside each category tell me how the radiation interacts with matter.

Type of radiation What it does to matter

__________________ high energy

______ frequency

__________________ ______ wavelength

__________________

__________________

__________________

__________________

__________________

__________________

__________________ low energy

______ frequency

______ wavelength

4. (10 pts) Dalton gave us four postulates concerning atomic structure and chemical reactions. Two of these have since turned into laws. Name these laws and explain in one or two sentences why they are so important.

5. (5 pts) What is the difference between a scientific hypothesis and a law? Write a well thought out and clear answer in the space provided below.

6. (5 pts) How many protons and neutrons do the following isotopes have?

# of protons # of neutrons

7. (15 pts) Match the best answer to each statement. Note: not all answers or statements may be needed and you may use a name twice or more.

a) Bohr _____ devised the gold foil experiment

b) J.J. Thompson _____ dreamed up the Earth, Wind, and Fire

atomic model

c) The Greeks _____ discovered electrons

d) Millikan _____ came up with the plum pudding model

e) Chadwick _____ disproved the plum pudding model

f) Einstein _____ explained how cathode ray tubes worked

g) George Bridges _____ devised the oil drop experiment

h) Schrondinger _____ first explained sharp line spectra

i) Mendeleev _____ developed the wave equation

j) Rutherford _____ explained what orbital shapes “look like”

_____ gave us the fuzzy ball atomic model

(two possible answers)

_____ their work allowed us to calculate the

mass of an electron (two answers)

_____ created the best Periodic Table

8. (10 pts) Using the Periodic Table on the next page, place the letter beside each item on the column, row, or area that best shows the location of each item.

a) elements with s-orbital electrons

b) elements with p-orbital electrons

c) elements with d-orbital electrons

d) elements with f-orbital electrons

e) alkali metals

f) alkaline earth metals

h) transition metals

i) halogens

j) noble gases

9. (10 pts) Give the name or symbol of the following.

Name Symbol

Hydroxide _______________

_______________ NO₃^-

Ammonium _______________

Sulfate _______________

_______________ CrO₄^-2

Carbonate _______________

Bicarbonate _______________

Fluoride _______________

_______________ As

Bromide _______________

10. (20 pts) Draw a Lewis dot structure for the following and fill in the preliminary table with data that will be used to determine the structure.

PO₄^3-

Number of valence electrons available _____

Molecular geometry ______________

Electronic geometry ______________

Lewis Dot Structure:

CO

Number of valence electrons available _____

Molecular geometry ______________

Electronic geometry ______________

Lewis Dot Structure: