Question

How many protons and how many neutrons are in$\text{(a)}{}^3\mathrm{He},\text{(b)}{}^{32}\mathrm{P},\text{(c)}{}^{32}\mathrm{S}\text{, and}\left(\mathrm{d}\right){}^{238}\mathrm{U}\text{?}$

Short answer

Therefore,

a.) 1

b.) 17

c.) 16

d.) 146

Step-by-step solution

Given information

$\text{(a)}{}^3\mathrm{He},\text{(b)}{}^{32}\mathrm{P},\text{(c)}{}^{32}\mathrm{S}\text{, and}\left(\mathrm{d}\right){}^{238}\mathrm{U}\text{?}$

Explanation (a)

The nucleus is made up of Z protons and A - Z neutrons, as we know.

a.) We have ³He

Atomic number is: 2

Number of protons is: 2

So, number of neutrons for ³He is: 3-2 = 1

Explanation (b)

b.) We have ³²P

Atomic number is: 15

Number of protons is: 15

So, number of neutrons for ³²P is: 32-15 = 17

Explanation (c)

c.) We have ³²S:

Atomic number is: 16

Number of protons is: 16

So, number of neutrons for ³²S is 32- 16 = 16

Explanation (d)

d.) We have ²²⁸U:

Atomic number is: 92

Number of protons is: 92

So, number of neutrons for ²²⁸U is 228-92 = 146