Question

In which of the following is number of neutrons correctly represented?​

Answer 1

Answer:

²³⁸₉₂U has 146 neutrons

Explanation:

To know which option is correct, we shall determine the number of neutrons in each case. This can be obtained as follow:

For ²⁴₁₂Mg:

Mass number (A) = 24

Proton number (P) = 12

Neutron number (N) =?

A = P + N

24 = 12 + N

Collect like terms

N = 24 – 12

N = 12

Thus, there are 12 neutrons in ²⁴₁₂Mg

For ⁷⁵₃₃As:

Mass number (A) = 75

Proton number (P) = 33

Neutron number (N) =?

A = P + N

75 = 33 + N

Collect like terms

N = 75 – 33

N = 42

Thus, there are 42 neutrons in ⁷⁵₃₃As

For ¹⁹₉F:

Mass number (A) = 19

Proton number (P) = 9

Neutron number (N) =?

A = P + N

19 = 9 + N

Collect like terms

N = 19 – 9

N = 10

Thus, there are 10 neutrons in ¹⁹₉F.

For ²³⁸₉₂U:

Mass number (A) = 238

Proton number (P) = 92

Neutron number (N) =?

A = P + N

238 = 92 + N

Collect like terms

N = 238 – 92

N = 146

Thus, there are 146 neutrons in ²³⁸₉₂U

Considering the options and the illustration made above, Only ²³⁸₉₂U has the correct number of neutrons written along side.