Question

nonmetals (reactivity trends) 1. arrange these nonmetals in order of most reactive to least reactive: fluorine (f), chlorine (cl), iodine (i), bromine (br). why does fluorine react more strongly than iodine? are they in the same group or the same period? 2. oxygen (o), sulfur (s), and selenium (se) are nonmetals. which one is the most reactive, and why? which group do they belong to? are they in the same period?

Explanation:

Step1: Recall non - metal reactivity trend

In the halogen group (Group 17 of the periodic table), reactivity decreases down the group. Fluorine is at the top, followed by chlorine, bromine, and iodine. So the order of reactivity for F, Cl, Br, I is F > Cl > Br > I.

Step2: Analyze oxygen - family elements

Oxygen (O) is in Group 16, Period 2; sulfur (S) is in Group 16, Period 3; selenium (Se) is in Group 16, Period 4. They are in the same group (Group 16, the chalcogens). Among them, oxygen is the most reactive due to its small atomic size and high electronegativity.

Step3: Answer the halogen reactivity question

Fluorine reacts more strongly than iodine because as we move down Group 17, the atomic size increases. The outermost electrons are farther from the nucleus and less strongly attracted, making it harder to gain an electron. Fluorine has a high electronegativity and a strong tendency to gain an electron to achieve a stable octet.

Answer:

1. F > Cl > Br > I
2. Oxygen, sulfur, and selenium are in Group 16. They are not in the same period. Oxygen is the most reactive among them.

Fluorine reacts more strongly than iodine because as you move down Group 17, atomic size increases and electronegativity decreases, reducing the ability to attract electrons.