Question

41 - 55: number of neutrons for sulphur-35

Explanation:

Step1: Recall atomic number of sulfur

Sulfur has an atomic number of 16.

Step2: Recall mass - number formula

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

Step3: Identify mass - number of sulfur - 35

For sulfur - 35, the mass - number $A = 35$.

Step4: Calculate number of neutrons

Since $p=16$ and $A = 35$, then $n=A - p$. Substituting the values, we get $n=35 - 16=19$.

Answer:

19