Question

question 1 of 25
an atom of aluminum (al) has an atomic number of 13 and a mass number of 27. how many neutrons does it have?
a. 13
b. 14
c. 40
d. 27

Explanation:

Step1: Recall the relationship formula

The mass number ($A$) is the sum of the number of protons ($Z$) and neutrons ($N$), i.e., $A = Z+N$.

Step2: Rearrange the formula to find neutrons

We can rewrite the formula as $N=A - Z$.

Step3: Substitute given values

Given that $A = 27$ and $Z = 13$, then $N=27 - 13=14$.

Answer:

B. 14