How are there 4 sulphate atoms in lithium sulphate?
The 4 is part of the sulphate ion – there is 1 S atom and 4 O atoms making up the sulphate ion. In the compound Li2SO4 you have 2 Li atoms combining with 1 SO4 ion to make the compound In a compound where there are multiple sulphate ions, it is written as follows: Aluminium sulphate: Al2(SO4)3 Not the brackets around the SO4. In this case you have 2 Al atoms combining with 3 SO4 ions to make the compound.
