Question

if an atom contains 3 protons, 4 neutrons, and 3 electrons, its mass number is

Explanation:

Step1: Recall the formula for mass number

Mass number ($A$) = number of protons ($p$) + number of neutrons ($n$)

Step2: Substitute the given values

Given $p = 3$ and $n = 4$
$A=3 + 4$

Step3: Calculate the mass number

$A = 7$

Answer:

7