1. How many electrons in the outer shell of group 1 elements?

Question 1 of 9

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

Question 2 of 9

3. 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

Question 3 of 9

4. Tungsten has the chemical symbol W. Suggest the chemical name of WO₃.

Question 4 of 9

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

Question 5 of 9

6. What is the atomic number of a chlorine atom?

Question 6 of 9

7. Calculate the relative formula mass(Mr) of ammonium nitrate (NH₄NO₃)

Question 7 of 9

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.

Question 8 of 9

9. What is meant by the term molecular formula?

Question 9 of 9