NAME
Average Atomic Mass Worksheet: show all work.
1) Rubidium is a soft, silvery-white metal that has two common isotopes, Rb and Rb. If the
abundance of Rb is 72.2% and the abundance of Rb is 27.8%, what is the average atomic mass of
85
85
rub,*™?
87
87
m
5
t
u
x
r
i
chan-^j
2) Uranium is used in nuclear reactors and is a rare element on earth. Uranium has three common
isotopes. If the abundance of U is 0.01%, the abundance of U is 0.71%, and the abundance of U is
99.28%, what is the average atomic mass of uranium?
234
235
238
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3) Titanium has five common isotopes: '"Ti (8.0%), Ti (7.8%), '"Ti (73.4%), *Ti (5.5%), ^ i (5.3%). What
is the average atomic mass of titanium?
47
4
4) Naturally occurring chlorine that is put in pools is 75.53 percent CI (mass = 34.969 amu) and 24.47
percent CI (mass = 36.966 amu). Calculate the average atomic mass.
35
37
0.1553(54.W»V Q.S^l(3b.9ldp)
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Name:
Hour:
Chemistry: Atoms, Mass, and the Mole
Date:
Use appropriate conversion factors and unit cancellation to solve the following problems. In order to get full
credit, you must show the set-up and include units in all quantities.
1. Find the number of atoms of phosphorus (P) in 3.44 moles of phosphorus.
2. What is the mass of 0.38 moles of cobalt (Co)?
3. How many moles of nickel (Ni) is 3.88 x 10 atoms of nickel?
25
4. How many atoms is 3.75 moles of iron (Fe)?
5. Find the number of moles of sodium (Na) in 145 g of sodium.
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6. How many moles is 0.55 g of magnesium (Mg)?
7. If you have 7.22 x 10 atoms of chromium (Cr), how many moles of chromium do you have?
8. What mass of tungsten (W) is 35 moles of tungsten?
9. How many atoms is 5.2 moles of titanium (Ti)?
10. How many moles of iron (Fe) is 5.98 x 10 atoms of iron?
11. What mass of molybdenum (Mo) is 6.68 moles of molybdenum?
12. How many moles is 586 g of rhenium (Re)?
13. How many atoms of palladium (Pd) is 400 g of palladium?
14. Find the mass of 4.55 x 10 atoms of vanadium (V).
15. Find the mass of 4.77 x 10 atoms of scandium (Sc).
16. Find the number of atoms in 36 g of germanium (Ge).
17. How many atoms are in 8500 g of selenium (Se)?
18. Find the mass of 1.43 x 10 atoms of polonium (Po).
Answers:
1. 2.07x10 atoms P
2. 22.4 g Co
3. 64.4molNi
4. 2.26 x 10 atoms Fe
5. 6.3molNa
6. 0.023 mol Mg
24
7.
8.
9.
10.
11.
12.
1.20molCr
6433 g W
3.13 x 10 atoms Ti
9.93molFe
641 g Mo
3.15molRe
24
13.
14.
15.
16.
17.
18.
2.26 X 10 atoms Pd
3.85 x 10 g V
3.6 g Sc
3.0 x 10 atoms Ge
6.48 x 10 atoms Se
4.96 x 10 g Po
24
6
23
25
6
Name
Date
Mole Practice #1
Period
1. How many sodium atoms are there in 51.85g of sodium?
3. How many carbon atoms are there in 47.26g of carbon?
4. How many aluminum atoms are there in 15.09g of aluminum?
5. How many iron (Fe) atoms are there in 189.15g of iron?
6. How many grams of arsenic are there when you have 8.96 x 10 arsenic atoms?
24
7. How many grams of magnesium are there when you have 4.27 x 10 magnesium atoms?
22
I
X:
8. How many grams of sulfur are there when you have 2.98x 10 sulfur atoms?
26
9. How many grams of phosphorous are there when you have 9.21 x 10 phosphorous atoms?
10. How many grams of cobalt (Co) are there when you have when you have 1.65 x 10 cobalt
atoms?
28
Period
Date
Name
Light Math
Directions: Solve the following problems using the equations found in your book or in your notes. Show
all work. Be sure to show units throughout your work and in your final answer.
1. What is the wavelength of an electromagnetic wave that has an energy of 6.54 x 10" J?
6
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"
'
1
2. How much energy (in joules) does a radio wave with wavelength 9.21m long carry?
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3. What is the frequency of an electromagnetic wave that has an energy of 4.23 x 10" J?
4. What is the wavelength of an electromagnetic wave that has an energy of 8.21 x 10" J?
8
5. What is the frequency of an electromagnetic wave that has an energy of 8.34 x 10" J?
18
IT
»
h
6. What is the wavelength of an electromagnetic wave that has an energy of 1.23 x 10
J?
Electron Configurations
Write the electron configurations in the table below.
Element
K
Electron configuration
Na
+
s2
B
K
+
CI"
c
Li
+
F"
Write the noble gas notation for the following elements
Element
K
Electron configuration
Na
S
LMtl 3s 3?^
5
B
Periodic Trends Worksheet
1. Rank the following elements in order from lowest to highest atomic radius: C, F, Be, 0.
2. Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).
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3. Rank the following elements in order from lowest to highest atomic radius: Ba, Be, Mg, Sr.
4.
Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).
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c,
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Ba
5. Rank the following elements in order from lowest to highest ionization energy: Ba, Be, Mg, Sr.
6. Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).
7. Rank the following elements in order from lowest to highest ionization energy: C, F, Be, 0.
8. Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).
9. Rank the following elements in order from lowest to highest electronegativity: C, F, Be, 0.
10. Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).
11. Rank the following elements in order from lowest to highest electronegativity: Ba, Be, Mg, Sr.
12. Explain why you ordered the elements the way that you did. (Talk about shielding or nuclear
charge).