Question

how many protons, neutrons and electrons are in boron?
p = 10, n = 5, e = 10
p = 5, n = 10, e = 10
p = 5, n = 5, e = 5

Explanation:

Step1: Recall atomic number concept

The atomic number of boron (B) is 5. The number of protons (P) is equal to the atomic number. So, P = 5.

Step2: Consider neutral - atom electron number

In a neutral atom, the number of electrons (E) is equal to the number of protons. So, E = 5.

Step3: Recall mass - number and neutron number relation

The most common isotope of boron has a mass number of 10. The mass number (A) is the sum of protons and neutrons (N), i.e., A=P + N. Given A = 10 and P = 5, then N=A - P = 10 - 5=5.

Answer:

P = 5, N = 5, E = 5