In Group 7, reactivity increases as you move in which direction?

In Group 7, reactivity increases as you move in which direction?

• A. Upwards
• B. Downwards
• C. Left
• D. Right

Answer: (A)

Group 7 contains the halogens, and their ability to gain an electron to form a negative ion is stronger for smaller atoms with a more effective nuclear pull. As you move up the group, atoms become smaller and the shielding effect is reduced, so the nucleus exerts a stronger attraction on an incoming electron. This makes it easier for the halogen to attract an electron and release more energy, increasing reactivity. Down the group, atoms are larger and shielding makes the attraction weaker, so reactivity decreases. Therefore, reactivity increases upwards in Group 7. For example, fluorine is more reactive than chlorine, which is more reactive than bromine and iodine.

Group 7 contains the halogens, and their ability to gain an electron to form a negative ion is stronger for smaller atoms with a more effective nuclear pull. As you move up the group, atoms become smaller and the shielding effect is reduced, so the nucleus exerts a stronger attraction on an incoming electron. This makes it easier for the halogen to attract an electron and release more energy, increasing reactivity. Down the group, atoms are larger and shielding makes the attraction weaker, so reactivity decreases. Therefore, reactivity increases upwards in Group 7. For example, fluorine is more reactive than chlorine, which is more reactive than bromine and iodine.