Chapter 5, Problem 81A

How many electrons are shown in each element’s electron-dot structure?
a. carbon   c. calcium
b. iodine   d. gallium

Interpretation Introduction

Interpretation:

The number of electron in electron dot structure of Carbon needs to be determined.

Concept introduction:

Electron- dot structure represents the valence electrons of an atom. The number of dots is identical to the number of valence electrons in the atom.

Answer to Problem 81A

The number of electrons in electron dot structure of Carbon is 4.

Explanation of Solution

Atomic number of Carbon is 6. Carbon shows the electronic configuration 1s²2s²2p². Thus there are 4 electrons in outer shell i.e. 2s and 2p. So it’s electron dot structure has 4 electrons.

Interpretation Introduction

Interpretation:

The number of electron in electron dot structure of Iodine needs to be determined.

Concept introduction:

Electron- dot structure represents the valence electrons of an atom. The number of dots is identical to the number of valence electrons in the atom.

Answer to Problem 81A

The number of electrons in electron dot structure of Iodine is 7.

Explanation of Solution

Atomic number of Iodine is 53. Iodine shows the electronic configuration [Kr] 4d¹⁰5s²5p⁵. Thus there are 7 electrons in outer shell i.e. 5s and 5p. So it’s electron dot structure has 7 electrons.

Interpretation Introduction

Interpretation:

The number of electron in electron dot structure of Calcium needs to be determined.

Concept introduction:

Electron- dot structure represents the valence electrons of an atom. The number of dots is identical to the number of valence electrons in the atom.

Answer to Problem 81A

The number of electrons in electron dot structure of Calcium is 2.

Explanation of Solution

Atomic number of Calcium is 20. Calcium shows the electronic configuration 1s²2s²2p⁶3s²3p⁶4s². Thus there are 2 electrons in outer shell i.e. 4s. So it’s electron dot structure has 2 electrons.

Interpretation Introduction

Interpretation:

The number of electron in electron dot structure of Gallium needs to be determined.

Concept introduction:

Electron- dot structure represents the valence electrons of an atom. The number of dots is identical to the number of valence electrons in the atom.

Answer to Problem 81A

The number of electrons in electron dot structure of Gallium is 3.

Explanation of Solution

Atomic number of Gallium is 31. Gallium the electronic configuration [Ar] 4s²3d¹⁰4p¹. Thus there are 3 electrons in outer shell i.e. 4s and 4p. So it’s electron dot structure has 3 electrons.