Answer:
H2O
=(1×2)+(8)
=20
Step-by-step explanation:
We have 1 Hydrogen(H) and 8 Oxygen(O)neutrons . Following the molecule formula, H2O, which means we have 2 Hydrogen that needs to times with 1 neutron;and we have only 1 Oxygen which has 8 neutrons. So 2 (H) have to times 1 and 1(O) have to times 8.