Question

Given the shell model of the atom, suggest a possible reason that Lewis proposed a maximum of two electrons for hydrogen and a maximum of eight for carbon, nitrogen, oxygen, and fluorine atoms?

Short answer

The Lewis's Model proposes a maximum of two electrons for hydrogen and eight for carbon, nitrogen, oxygen, and fluorine, based on the electron capacity of their respective energy levels. Hydrogen, as the simplest element, has just one energy shell, which can hold up to two electrons. On the other hand, carbon, nitrogen, oxygen, and fluorine possess two energy shells where the second shell can accommodate up to eight electrons while considering the octet rule.

Step-by-step solution

Understand the Characteristics of Hydrogen

Hydrogen is the simplest atom, having only one proton in its nucleus. Accordingly, it has only one energy level.

Apply the Lewis Model to Hydrogen

The Lewis Model suggests that the energy level of hydrogen can accommodate a maximum of two electrons. Thus, hydrogen can have one or two electrons, depending upon whether it is neutral or ionized.

Understand the Characteristics of Other Elements

Carbon, nitrogen, oxygen, and fluorine have two energy shells, the first shell can hold up to two electrons, and the second one is capable to hold up to eight electrons.

Apply the Lewis Model to Other Elements

Applying the Lewis Model to these atoms suggests that, while the first two electrons would occupy the inner shell, the remaining ones would go to the second shell. Therefore, these elements can hold a maximum of eight electrons in their second shell.