Question

The electronic configurations of three elements X, Y and Z are:

X: 2

Y: 2, 8, 7

Z: 2, 8, 2

Which of the following is correct regarding these elements?

Options

• X is a metal.

• Y is a metal.

• Z is a non-metal.

• Y is a non-metal and Z is a metal.

Answer 1

Y is a non-metal and Z is a metal.

Explanation:

Element Y has 7 valence electrons in its outermost shell, meaning it needs to gain 1 electron to complete its octet, which is a characteristic property of a non-metal. Element Z has 2 valence electrons in its outermost shell, which it can easily lose to achieve stability, making it a metal. Element X has a stable, filled outer shell and represents the unreactive noble gas helium, meaning it is neither a metal nor a reactive non-metal.