Chapter 9, Problem 129A

Interpretation Introduction

Interpretation:

The difference between an electron configuration and electron-dot structure needs to be explained.

Concept introduction:

An element's electron configuration determines how its atomic orbitals exchange electrons. Electron-dot structure represents the valence electrons of an element. Valence electrons are outermost electrons which takes part in chemical reaction.

Answer to Problem 129A

Electron-dot structure consists of the element’s symbol, which describes the atomic nucleus and inner-level electrons, enclosed by dots denoting all of the atom’s valence electrons.

The electron configuration symbol indicates the principal energy level and energy sublevel connected with each of the atom’s orbitals and introduces a superscript denoting the number of electrons in the orbital.

Explanation of Solution

Electron configuration is the arrangement of electrons of an atom or molecule. Atomic number of Na is 11. Therefore, its electron configuration is as follows:

${\text{Na=1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{1}}$

Electron-dot structure indicates valence electrons by dots placed around the chemical symbol of the element. The structure of beryllium is given below:

Atomic number of Be is 4. It has filled 1s orbital with two electrons. Electron dot-structure represents the electrons of outermost shell. It has two electrons in there valence shell.

Conclusion

In writing an atom’s electron-dot structure, dots indicate valence electrons. They are placed one at a time on the four sides of the symbol and then paired up until all are used. Electron configuration refers to the whole electron orientation in an atom of particular element.