How many atoms are there in 5K2CO3

Depends on what are you refering to

Explanation:

So depending on what you are looking for (your question is quite vauge)

there are 5 atoms of the comopound (K2CO3)

within that compound, there are 2 atoms of Potassium and 1 atom of Carbonate. Within Carbonate there are 4 atoms (1 carbon and 3 oxygens)

so answers may be

5, 15, or 25.

I hope this helps.