Electron Configuration in Ammonium Ion and Methane

Steps:

• Determine electron count for NH4+: Nitrogen (7 electrons) + 4 hydrogens (4 electrons) = 11 total, minus 1 for +1 charge = 10 electrons.
• Determine electron count for CH4: Carbon (6 electrons) + 4 hydrogens (4 electrons) = 10 electrons.
• Verify other options: A involves standard reaction but specifies "gas" incorrectly in aqueous context; B confuses AgI solubility (it's insoluble); D misstates geometry (tetrahedral, not square planar).
• Conclude C matches exactly.

Why C is correct:

• Both NH4+ and CH4 have 10 valence electrons, following the octet rule for stable structures (NH4+ via dative bonding, CH4 via covalent bonds).

Why the others are wrong:

• A: Reaction produces NH3(aq), not necessarily gas without heating.
• B: AgI is insoluble in concentrated aqueous ammonia, unlike AgCl.
• D: NH4+ is tetrahedral, not square planar; it does have one dative bond but shape is incorrect.

Final answer: C