Question

1. an isotope has 15 protons, 16 neutrons, and 15 electrons. which of the following is the isotope? (4pts) ☐ p-30 ☐ p-31 ☐ s-30 ☐ s-31

Explanation:

Step1: Identify element from protons

The number of protons (15) equals the atomic number, so the element is phosphorus (P).

Step2: Calculate mass number

Mass number = protons + neutrons = $15 + 16 = 31$

Step3: Match to isotope option

The isotope is phosphorus-31, as protons = electrons (neutral atom).

Answer:

$\boldsymbol{P-31}$