Question

which of the following combination of elements is the most reactive? (1 point) k and i cs and br cs and i na and br

Explanation:

Step1: Analyze the reactivity of alkali metals

Alkali metals (Li, Na, K, Cs etc.) become more reactive as we go down the group. So, Cs is more reactive than K and Na.

Step2: Analyze the reactivity of halogens

Halogens (F, Cl, Br, I, At) become less reactive as we go down the group. So, Br is more reactive than I.

Step3: Determine the most reactive combination

Since Cs is a very reactive alkali metal and Br is a relatively reactive halogen among the given options, the combination of Cs and Br will be the most reactive.

Answer:

Cs and Br