Chapter 3, Problem 58A

Interpretation Introduction

Interpretation :

The atom with ion having -2 charge and 18 electrons needs to be identified.

Concept Introduction :

The number of protons present in the nucleus is representing the atomic number of the element. The mass number of an element is the total number of protons and neutrons present in the nucleus of an atom.

Answer to Problem 58A

  $\text{S}$ atom is converted into ${\text{S}}^{\text{2-}}$an ion with a gain of two-electron, so the total electron is $\text{18}$and carries the $\text{-2}$charge.charge.

Explanation of Solution

Ions – it is a charge form of an element, the $\text{(+)}$sign is denoted that one electron is lost by the element, and the $\text{(-)}$sign is denoted that one electron is gained by the element.

The $\text{S}$atom accepts two electrons and form ${\text{S}}^{\text{2-}}$ion, that carries -2 charge and have $\text{18}$electrons.

Conclusion

The atomic number of an element is calculated by the number of protons, and for the mass number, the number of protons and neutrons is required. The number of electrons of an atom can be changed by the loss or gain of electrons.