Question

question 1
a nucleus with an atomic number of 4 and a mass number of 9 must have
hint: total number of neutrons in a given isotope = mass number - atomic number = z - a
a. 4 neutrons
b. 9 neutrons
c. 5 neutrons
d. 13 neutrons

Explanation:

Step1: Recall the formula for neutron number

The number of neutrons $n$ in an atom is given by the formula $n = \text{Mass number}-\text{Atomic number}$.

Step2: Substitute given values

Given that the atomic number $Z = 4$ and the mass number $A=9$. Then $n=9 - 4$.

Step3: Calculate the result

$9-4 = 5$.

Answer:

C. 5 neutrons