Question

Elements occur in a number of isotopic forms. In this problem, you will learn about the notation used to distinguish different isotopes.How many protons Z and how many neutrons N are there in a nucleus of the most common isotope of silicon, 28/14Si?

Answer 1

Answer:

• There are 14 protons (Z) and 14 neutrons (N) in a nucleus of the most common isotope of silicton.

Explanation:

The notation of the most common isotope of silicon is:

• $^{28}_{14}Si$

The superscript, 28, to the left of the chemical symbol, Si, is the mass number, usually identified with the symbol A, and it is the sum of the protons and neutrons.

The subscript, 14, to the left of the chemical symbolr, Si, is the atomic number, Z, which is the number of protons.

Then, you have this equation:

• mass number = number of protons + neutrons, or, in symbols:

• A = Z + N

The number of protons is the same for any isotope of the same element. This is, all the isotopic forms of silicon have the same number of prtons: 14

The number of neutrons is determined from the equation A = Z + N, solving for N:

• N = A - Z = 28 - 14 = 14.

Hence, the most common isotope of silicon has 14 protons and 14 neutrons.