Question

how many neutrons are in the nucleus of a phosphorus atom with a mass number of 31? enter your answer in the box.

Explanation:

Step1: Recall the formula for neutrons

The number of neutrons ($n$) in an atom is calculated by the formula $n = \text{mass number} - \text{atomic number}$.

Step2: Find the atomic number of phosphorus

The atomic number of phosphorus (P) is 15.

Step3: Calculate the number of neutrons

Using the formula, with mass number = 31 and atomic number = 15, we have $n = 31 - 15 = 16$.

Answer:

16