Question

Explain the trend in the reducing ability of the halogens. Which of the following correctly describes the trend in the reducing ability of the halogens as you move down the Group 17 (VIIA) of the periodic table?

Option 1: The reducing ability decreases as you move down the Group 17.
Option 2: The reducing ability remains constant across the Group 17.
Option 3: The reducing ability increases as you move down the Group 17.
Option 4: The reducing ability of the halogens does not follow a specific trend within Group 17.

Answer 1

The reducing ability of halogens increases as you move down Group 17 of the periodic table, opposite to Groups 1 and 2 metals' reactivity trend.

Step-by-step explanation:

The trend in the reducing ability of halogens as you move down Group 17 (VIIA) of the periodic table is that it increases. This trend is opposite to the trend in reactivity of metals in Groups 1 and 2, where reactivity increases up a group.

The reason for the increase in reducing ability among halogens is due to their electron configuration of ns²np5, which means they have one less electron than the noble gases and are very eager to gain an electron to achieve a full outer shell. As you move down the group, the atomic size increases, which makes the outer electrons less tightly held to the nucleus and more easily donated. This explains why elements such as iodine are better reducing agents than fluorine.