Calculations quiz

1. Write the electronic configuration of argon

2. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid used?

3. An oxide of nitrogen contains 26% nitrogen and 74% oxygen and has a relative molecular mass of 108. Find the empirical and molecular formulae for the oxide.

4. Calculate the relative formula mass(Mr) of zinc phosphide (Zn₃P₂)

5. What is meant by the term empirical formula?

6. State the mass and charge of a proton

7. What is the empirical formula of a compound in which 0.48 g of carbon combines with 0.08 g of hydrogen and 0.64 g of oxygen?

8. A sample of bromine contained the two isotopes in the following proportions: bromine-79 = 50.7% and bromine-81 = 49.3%. Calculate the relative atomic mass of bromine

9. How many protons in a potassium atom?