Which group and period does the element belong if the electronic configuration of an element in its -2 oxidation state is 1s²2s²2p⁶3s²3p⁶?

Solution

Step 1: Identify the Period

The principal quantum number n = 3 indicates that the outermost electrons are in the third energy level. This places the element in the third period.

Thus, to which period does this element belong? It belongs to period 3.

Step 2: Determine the Group

1. The given configuration represents the element after gaining 2 electrons, meaning it has a full octet (like Argon, 3p⁶).
2. To find the neutral element (before gaining electrons), remove the two extra electrons. The neutral configuration becomes 1s²2s²2p⁶3s²3p⁴, which corresponds to Sulfur (S).
3. Sulfur is in the 16th group (Group VI A in older notation) of the periodic table because it has 6 valence electrons (2 from 3s² and 4 from 3p⁴).

Key Points

• The element belongs to the p-block because the last electron is filled in a p-orbital.
• To which period does this element belong? The element belongs to period 3 based on n = 3.
• It is part of Group 16 due to its valence electron configuration.

Final Answer

Group: 16 (VI A)
Period: 3 (To which period does this element belong? Period 3).
Block: p-block

Sulfur (S) is the element that satisfies the given configuration in its -2 oxidation state.