Answer
See the explanation
Work Step by Step
Formulae
Protons = Z = 8
Neutrons = A − Z
Electrons in neutral atom = Z = 8
Group number of oxygen = 16 (group 16 = chalcogens)
Isotope notation: $^A_Z X$
Calculate for each isotope
(i) Oxygen-16
Protons = 8
Neutrons = 16 − 8 = 8
Electrons = 8
Group = 16
Symbol:$^{16}_8O$
(ii) Oxygen-17
Protons = 8
Neutrons = 17 − 8 = 9
Electrons = 8
Group = 16
Symbol: $^{17}_8O$
(iii) Oxygen-18
Protons = 8
Neutrons = 18 − 8 = 10
Electrons = 8
Group = 16
Symbol: $^{18}_8O$
