Chemistry Chapter 3 Study Guide
11/4/2014
Name:___________________________________________ Per____________
Directions: Put the number of the definition below into the square with the appropriate term. Check
your answers by adding the numbers to see if all the sums of all rows and columns add up to the same
number, the Magic Number.
Democritus
Dalton
Thomson
Nuclide
Total
Rutherford
Proton
Atom
Atomic Number
Total
Isotope
Neutron
Nucleus
Alpha Particle
Total
Electron
Carbon-12 nuclide
1 AMU
Average atomic
mass
Total
Total:
Total
Total
Total
Magic Number:___________________
1. Represented by a symbol; all are found on the periodic table.
2. Made a mental model of the atom by thinking about repeatedly cutting a piece of gold in half until he
reached a basic particle that could no longer be cut in half and still be gold; he called the smallest
particle atomos; Greek philosopher.
3. Used by Rutherford in his experiment; made of 2 protons and 2 neutrons.
4. Exactly 1/12 the mass of a carbon-12 atom.
5. The positive particle in the nucleus of an atom.
6. The dense, tiny, positively charged core of an atom; contains protons and neutrons.
7. Proposed an atomic theory consisting of 5 points that explained the law of conservation of mass, the
law of definite proportions, and the law of multiple proportions; English school teacher.
8. Discovered the nucleus using his gold foil experiment.
9. The weighted average of the atomic masses of the naturally occurring isotopes of an element.
10. The atom that is the standard for the relative atomic mass scale. One of these atoms has a mass of
exactly 12 amu.
11. The smallest particle of an element that still retains the chemical properties of that element.
12. A general term for any isotope of any element.
13. Atoms of the same element that have different masses.
14. Mass of protons and neutrons.
15. The number of protons in the nucleus of each atom of an element.
16. The negative particle that circles the nucleus.
17. The neutral particle in the nucleus of an atom.
18. Proposed the “plum pudding” model of the atom; discovered the electron.
1. Explain each of the following in terms of Dalton’s atomic theory:
a. The law of conservation of mass
b. The law of definite proportions
c. The law of multiple proportions
2. How does modern atomic theory differ from Dalton’s atomic theory?
3. Describe Thomson’s experiment and what he discovered with it. State the evidence that led to
his conclusions.
4. Describe Millikan’s experiment and what he discovered with it. State the evidence that led to
his conclusions.
5. Describe Rutherford’s experiment and what he discovered with it. State the evidence that led
to his conclusions.
6. Complete the following table describing properties of subatomic particles:
Particle
Location in atom
Relative electric
charge
Mass Number
Relative mass
(amu)
7. Give the symbol and number of protons in one atom of:
a. Lithium________________________
b. Bromine_______________________
c. Iron___________________________
d. Copper________________________
e. Oxygen________________________
f.
Mercury_______________________
8. Give the symbol and number of electrons in a neutral atom of:
a. Uranium_______________________
b. Chlorine_______________________
c. Boron_________________________
d. Iodine_________________________
e. Antimony______________________
f.
Xenon_________________________
9. Give the nuclear symbol and hyphen notation for each of the following isotopes:
a. Mass number 137 and atomic number 56
b. 83 protons and 126 neutrons
c. 50 electrons and 69 neutrons
10. If you know only the following information can you always determine what the element is? (Yes
or No):
a. Number of protons _________
b. Number of neutrons_________
c. Number of electrons in a neutral atom_____________
d. Number of electrons_________
11. What is the average atomic mass of hafnium if , out of every 100 atoms, 5 have a mass of 176
amu, 19 have a mass of 177 amu, 27 have a mass of 178 amu, 14 have a mass of 179 amu, and
35 have a mass of 180.0amu? Give your answer to 2 decimal places.
12. Calculate the average atomic mass of magnesium, using the following data. Give your answer to
3 decimal places.
Isotope
mass(amu)
relative abundance (%)
Mg-24
23.985
78.70
Mg-25
24.986
10.13
Mg-26
25.983
11.17
13. Lithium has two naturally occurring isotopes: lithium-6 and lithium-7. If the average atomic
mass of lithium is 6.941 amu, which isotope is the most abundant? Explain how you know.
14. The largest producing gold mine in the world is in Papua, Indonesia. Gold has an average atomic
mass of 196.96654 amu. Of all of the gold atoms mined in Papua, Indonesia in one year, what
percentage of them will have a mass of 199.96654amu?
15. .Describe what the mole is and why it is useful.
16. How do molar mass and atomic mass relate? What makes this relationship possible?
17. Determine the mass in grams of each of the following. (Don’t forget to use sig figs!)
a. 3.00 mol Al
b. 2.25 x 1024 atoms Zn
18. Determine the moles of each of the following:
a. 40.1 g Ca
b. 2.25 x 1024 atoms Zn
19. Determine the number of atoms of each of the following:
a. 6.50 mol Cu
b. 150 g S
20. You are in the lab and measure out the following masses of different elements. In each group,
identify which one contains the greatest number of atoms. Put an X in the appropriate blank.
a. 9.012182 g Beryllium _________
118.710 g Tin _________
Same ________
b. 63.546 g Cu __________
36.443 g Mg__________
Same________
c. 13.882 g Lithium_________
175.24 g Sr _________
Same________