CHEM 150
Assignment #1
(Due October 3rd, in class)
1) Calculate the atomic mass of magnesium, using the given data for the percentage abundance and
mass of each isotope:
Magnesium:
78.70%
10.13%
11.17%
2) Write the electron configuration for gallium, Ga. Draw its orbital energy diagram and answer the
following questions:
a) How many unpaired electrons are contained in an atom of gallium?
b) What is the electron configuration of Ga3+?
3) Calculate the charge on the metal ion in each of the following ionic compounds. (Hint: start off by
determining the charge of the non-metal part of the formula and then use the technique we looked at in
today’s class to figure out the metal ion’s charge.)
a) SnCl4
b) Fe2O3
4) Complete the following table:
Positive ion
Negative ion
Chemical formula
name
Cu2SO4
Lithium nitride
Al3+
S2Co3(PO4)2
Challenge question
5) A child with severe poison ivy weighs 25 kg. Benadryl is given orally, 5 mg/kg/day, every 6 hours.
Benadryl is available as a 12.5 mg/5 mL solution. What dose (mL) should be given? (hint: if you treat the
“5 mg/kg/day” conversion factor as 5 mg = 1 kg*1day, you can easily solve using dimensional analysis.)