Atomic structure of isotopes and ions

Steps:

• Germanium (Ge) has atomic number Z = 32, so 32 protons in the nucleus.
• Nucleon number A = 70, so neutrons = A - Z = 70 - 32 = 38.
• Neutral Ge atom has 32 electrons (equal to protons).
• Selenium (Se) has Z = 34; Se²⁻ ion has gained 2 electrons, so 36 electrons total.

Why A is correct:

• Not enough information; neutral Ge has 32 electrons, but Se²⁻ has 36 (Z + 2 from charge), so numbers differ.

Why the others are wrong:

• B: Zn has Z = 30; Zn-74 has neutrons = 74 - 30 = 44, not 38.
• C: "Wd" is not a recognized element symbol (tungsten is W, Z=74); ambiguous, cannot verify proton comparison.

Final answer: Not enough information.