Question

question 4. what is the mass number of a helium atom that has two protons and two neutrons? mass number =

Explanation:

Step1: Recall mass - number formula

The mass number ($A$) of an atom is the sum of the number of protons ($p$) and neutrons ($n$), i.e., $A=p + n$.

Step2: Identify values of $p$ and $n$

Given that $p = 2$ and $n=2$.

Step3: Calculate mass number

Substitute the values into the formula: $A=2 + 2=4$.

Answer:

4