Worksheet 2 Atomic Structures, the Periodic Table and Naming of Compounds

Topics covered in this worksheet: atomic structures, , the periodic table and naming of compounds.

Symbol to represent =

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 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 name, group and 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. 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 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 atoms are in 20.0 g of acetic acid?

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