Question

The diagram shows an electron shell model of a sodium atom.

A central purple circle labeled N a has 3 concentric rings around it. The inner ring has 2 small green spheres. The middle ring has 8 small green spheres. The outer ring has 1 small green sphere.

How would the model change as the atom forms bonds?

The third shell would have eight electrons after the atom gains seven electrons to fill the outermost shell.
The third shell would be empty so that the eight electrons in the second level would be outermost after the atom loses one electron.
The first and third shells would be empty so that the atom would have eight electrons in its remaining shell after the atom loses three electrons.
The first shell would have two electrons and the second shell would have six electrons after the atom loses three electrons.

Answer 1

The correct choice is: "The third shell would be empty so that the eight electrons in the second level would be outermost after the atom loses one electron."

Explanation: Neutral sodium has 11 electrons (2, 8, 1). When it forms its common +1 ion (loses one electron), the configuration becomes 2, 8 — the third shell is empty and the second shell is the outermost full shell.