Break down the table into smaller sections. Memories period by period or if you like by group (like halogens or noble gases).
Just say the elements in order everyday 1-10 then when you get those 11-20 and continued.
Answer:
28
Explanation:
28 is correct. (NH4)2 is equal to 10 atoms. (8 H and 2 N ) CO3 is equal to 4 atoms. (1 C and 3 O) That's 14 atoms. But it's two molecules of this. So you just multiply by the number of molecules (2), and you get 28.
I think it would seeing as you typicaly have to use a match to light a gas burner