1.23 Understand how the formulae of simple compounds can be obtained experimentally, including metal oxides, water and salts containing water of crystallisation

• Weigh the compound
• Remove one element of it through a reaction
• Weigh again
• If the first weight [mass] of the compound is AB and the second weight [mass] is A, you can work out B by: AB-A=B
• Work it out by dividing the weight by the relative atomic mass

1.12 Calculate the relative atomic mass of an element from the relative abundances of its isotopes

(% of isotope 1 x mass of isotope 1) + (% of isotope 2 x mass of isotope 2) ÷ 100

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