Calculations quiz

1. How many electrons in an argon atom?

2. A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the relative atomic mass of carbon

3. Which particle(s) in an atom has a negative charge?

4. What is an atomic number?

5. Calculate the relative formula mass(Mr) of a molecule of bromine (Br₂)

6. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid lifted from time to time?

7. What is meant by the term empirical formula?

8. A compound that contained 24.24% Carbon. 4.04% Hydrogen and 71.72% Chlorine and has a relative molecular mass of 99. Calculate the empirical formula and the molecular formula.

9. Work out the empirical formula of an oxide of chlorine contains 7.1 g of chlorine and 1.6 g of oxygen.