Chapter 2.3, Problem 2.15P

(a)

Interpretation Introduction

Interpretation:

The number of protons for the three isotopes of magnesium has to be given.

Concept Introduction:

Protons:

A proton is one of three main particles that make up the atom.  Protons are a tiny, dense region at the center of the atom.  Protons have a positive electrical charge of $+1$ and a mass of 1 atomic mass which is $\text{1}{\text{.62×10}}^{\text{-27}}$ kilograms.

(b)

Interpretation Introduction

Interpretation:

The number of electrons for the three isotopes of magnesium has to be given.

Concept Introduction:

Electrons:

Electrons have an electric charge of $\text{-1}$, which is equal but opposite to the charge of a proton, which have an electric charge of $\text{+1}\text{.}$  All atoms have the same number of electrons as protons, so the positive and negative charges cancel out making atoms electrically neutral.

(c)

Interpretation Introduction

Interpretation:

The atomic number for the three isotopes of magnesium has to be given.

Concept introduction:

Atomic number (Z):

Atomic number of an element is the number of protons found in the nucleus of every atom of that element.

(d)

Interpretation Introduction

Interpretation:

The mass number and the isotope symbol for three isotope of Magnesium have to be given.

Concept Introduction:

Mass number (A):

Mass number of an element is defined as the total number of protons and neutrons in an atom.

  $\text{A=Number}\text{of}\text{protons}\text{+}\text{Number}\text{of}\text{neutrons}$