The correct answer is d. 8p+; 9n; 10e−
Oxygen exists in three isotopes ¹⁶O, ¹⁷O and ¹⁸O. The atomic number of oxygen is 8. It means its nuclei has 8 protons. The given is oxide⁻² anion. This means it has gained 2 electrons. Thus, oxide anion have 8 protons and 10 (8+2) electrons. The number of neutrons depends on the isotope, in this question mass number is given¹⁷O. The mass number is the sum of the protons and neutrons in the nucleus. Hence, number of neutrons oxide anion will be 17-8 = 9 neutrons.