When a reaction system is at equilibrium: a. there is no more chemistry happening. b. the amounts of reactants and products are exactly equal. c. the reaction rate in the forward direction is at a maximum. d. the reaction rate in the reverse direction is at a minimum. e. the rates of the reaction in the forward and reverse directions are exactly equal.

Option (e) is the correct answer.

Explanation:

Equilibrium is defined as the state of a chemical reaction in which the rate of forward reaction is equal to the rate of backward reaction.

The state of equilibrium is represented by a double sided arrow as "" in a chemical equation.

For example,

Therefore, we can conclude that when a reaction system is at equilibrium then the rates of the reaction in the forward and reverse directions are exactly equal.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6