box 3: nonmetals reactivity trend\ndraw an arrow showing: most reactive → least reactive\nlist 3 nonmetals…

Explanation:

Step1: Non - metals reactivity trend

In the periodic table, non - metal reactivity decreases down a group and increases across a period from left to right. Fluorine is the most reactive non - metal.

Step2: List non - metals

Fluorine (F), Chlorine (Cl), Bromine (Br). Fluorine is most reactive as it has a high electronegativity and a small atomic radius, making it easy to gain an electron. Chlorine is less reactive than fluorine but more reactive than bromine as the atomic size increases down the group and the ability to attract electrons decreases.

Step3: Element group and period info

Sodium (Na) is in Group 1, Period 3, and is highly reactive as it has one valence electron and wants to lose it to achieve a stable octet. Chlorine (Cl) is in Group 17, Period 3, and is highly reactive as it needs one electron to complete its octet. Potassium (K) is in Group 1, Period 4, and is highly reactive due to its single valence electron and larger atomic size compared to sodium. Calcium (Ca) is in Group 2, Period 4, and is reactive as it has two valence electrons to lose, but less reactive than Group 1 elements.

Element	Group	Period	Reactivity (High/Low)
Sodium (Na)	1	3	High
Chlorine (Cl)	17	3	High
Potassium (K)	1	4	High
Calcium (Ca)	2	4	Moderate - High

Answer:

For non - metals in order of reactivity: 1. Fluorine (F), 2. Chlorine (Cl), 3. Bromine (Br)

Element	Group	Period	Reactivity (High/Low)
Sodium (Na)	1	3	High
Chlorine (Cl)	17	3	High
Potassium (K)	1	4	High
Calcium (Ca)	2	4	Moderate - High