Question

which symbol below correctly identifies an element with 16 protons, 18 neutrons, and 18 electrons? a. $_{16}^{16}ar^{+1}$ b. $_{18}^{16}ar^{-1}$ c. $_{18}^{34}s^{+2}$ d. $_{16}^{34}s^{-2}$

Explanation:

Step1: Determine element by protons

Atomic number = protons = 16 → element is S (sulfur).

Step2: Calculate mass number

Mass number = protons + neutrons = 16 + 18 = 34.

Step3: Determine charge

Charge = electrons - protons = 18 - 16 = -2 (anion).

Step4: Identify correct symbol

Symbol: \(_{16}^{34}S^{-2}\) (matches option d).

Answer:

d. \(_{16}^{34}S^{-2}\)