Tolong jawab kimia SMP kelas 9.

1. 40Ca20
Proton: 20
Elektron: 20
Neutron: 40 - 20 = 20

2. 16O8 2-
Proton: 8
Elektron: 8 + 2 = 10
Neutron: 16 - 8 = 8

3. 27Al13 3+
Proton: 13
Elektron: 13 - 3 = 10
Neutron: 27 - 13 = 14

unsur Ca:
p=20
e=p=20
n=40-20=20

ion O:
p=8
e=8-(-2)=10
n=16-8=8

ion Al:
p=13
e=13-3=10
n=27-13=14

semoga membantu