The Rules

Important Ground Rules for Completing these Quizzes

Please read!

Only use the data from the A Level Periodic Table which shows the appropriate number of decimal places and correct spellings. All exam boards have a common Periodic Table at A level.

Entering numerical answers

  • All your answers should be to 3 significant figures where relevant.
  • Use the relative atomic mass values from the A Level Periodic Table to calculate relative molecular/formula masses.

Carry out your calculations on paper. Check them carefully for spelling and significant figures before entering your answers into the quiz.

Some examples are offered below. Please look at them.

Example 1

Question: Calculate the mass present in 0.250 mol of zinc.

Answer: 0.250 x 63.5=15.875

You should only enter 15.9 Any other answer will be marked as incorrect so be careful!

Example 2

Question: Calculate the mass in 1.50 mol of chromium

Answer: 1.50 x 52.0=78

You should only enter 78.0 Any other answer will be marked as incorrect so be careful!

Example 3

Question: Calculate the number of moles of chromium present in 0.780 g of chromium

Answer: 0.78/52.0=0.015

You should only enter 0.0150        Any other answer will be marked as incorrect so be careful!

Example 4

Question: Calculate the relative formula mass of calcium carbonate CaCO­3

Answer: 40.1 + 12.0 + (3 x 16.0) = 100.1

You should only enter 100.1        Note that this is to 4 significant figures. This is the level of accuracy provided by the A Level Periodic Table.

Entering Chemical Names

There are some simple rules.

  • All letters are lowercase.
  • The roman numerals are uppercase versions of the letters v & i
  • There is one space each side of the bracketed roman numerals and the text.
  • Correct spellings of elements are only those on your periodic table. e.g. sulfur not sulphur.

Example 1

Question:    Name a compound with the formula Fe2(SO4)­3

Answer:       iron (III) sulfate

Example 2

Question:    Name a compound with the formula MnO2

Answer:       manganese (IV) oxide

Entering Chemical Formulae

There are some simple rules.

You are unable to enter subscripts or superscripts into the quiz answer box.

To enter a chemical formula, ignore subscripts and superscripts.

Example 1

Question:    Write down the formula hydrogen peroxide.

Answer:       H2O2

Example 2

Question:    Write down the formula aluminium nitrate

Answer:       Correct formula is Al(NO­3)3

You enter    Al(NO3)3