Question

1. the electron - dot symbol below represents an ion of element x.

which of the following could be element x?

Explanation:

Step1: Analyze the electron - dot symbol

The ion has a negative charge (\(X^{-}\)), which means it has gained one electron. The electron - dot symbol shows that the ion has a full outer shell of 8 electrons (octet rule).

Step2: Consider the valence electrons of each element

• Hydrogen (H): Has 1 valence electron. If it gains 1 electron, it would have 2 electrons (duet rule, not octet).
• Iodine (I): Is in Group 17 (halogen). Has 7 valence electrons. Gaining 1 electron gives it 8 valence electrons (\(I^{-}\)).
• Nitrogen (N): Has 5 valence electrons. Gaining 3 electrons (\(N^{3 -}\)) would give it 8 valence electrons.
• Potassium (K): Is in Group 1. Has 1 valence electron. It loses 1 electron (\(K^{+}\)) to achieve a stable configuration.

Answer:

I