Worksheet 2 Atomic Structures, the Periodic Table and Naming of Compounds
Topics covered in this worksheet: atomic structures, isotopes, the periodic table and naming of compounds.
Symbol to represent isotope =
Where, A = Mass number = # Protons + # Neutrons and Z = Atomic Number = # Protons
1. Using the Periodic Table, fill in the missing information in the chart, below.
Symbol atomic mass protons Neutrons electrons charge W 184 2+ 35 45 0 197 118 78 128 52 54
2. For each of the numbered species that is a neutral atom, represent its composition in the form
, which of these species are isotopes? Explain why?
#1 #2 #3 #4 #5 #6 #7 No. protons 16 20 19 18 20 22 20 No. neutrons 18 20 21 22 24 26 28 No. electrons 18 20 18 17 18 22 20
3. For the following elements, identify the group name, group and period number for each of the following elements, and classify the element as a metal or non-metal
a) Ga b) P c) I d) Ra e) Li f) La g) Xe
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4. Please fill the correct name / chemical formula for the following table Chemical Formula Compound/Molecule Name
Cr2S3
I2O5
SiCl4
Ba(NO3)2
KClO3
Magnesium Nitride
Ammonium phosphate
Strontium sulfite
Hydrogen peroxide
Xenon hexafluoride
5. Indium has two naturally occurring isotopes and a weighted average atomic mass of 114.82 amu . One of the isotopes has a mass of 112.9043 amu. Which is likely to be the second isotope: 111In, 112In, 114In, or 115 In?
6. Two naturally occurring isotopes of copper are copper-63, mass 62.9298 amu, and copper- 65, mass 64.9278 amu. What must be the percent natural abundances of the two isotopes if the atomic mass of copper on the periodic table is 63.546 amu?
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7. The formula for acetic acid (i.e. vinegar) is C2H4O2 (it is also commonly written as
CH3COOH). a) What is the molecular mass of acetic acid?
b) if you have 5.00 x 1026 molecules of acetic acid, what would the mass be in kg?
c) how many oxygen atoms are in 20.0 g of acetic acid?
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