Answer:
Explanation:
An atom is the smallest indivisible particle that takes part in any chemical reaction. They are easily identified distinctively as elements in a compound.
The subscripts accompanying a chemical symbol shows the number of atoms of elements combining to give a compound:
Compound Elements Number of atoms
KBr K Br 2
C₁₂H₂₂O₁₁ 12(C) 22(H) 11(O) 12 + 22 + 11 = 45
KAlSi₃O₈ 1(K) 1(Al) 3(Si) 8(O) 1 + 1 + 3 + 8 = 13
Ag₃PO₄ 3(Ag) 1(P) 4(O) 3+ 1 + 4 = 8
CH₃CO₂C₆H₄COOH 9(C) 8(H) 4(C) 9+8+4 = 21