Why are some mystery elements easier to identify than others?

They give colors to their salts.

Explanation:

When the reaction occurs and the formation of salts taken place then some elements give distinct colors to their salts while the reaction taking place.

So when we look out these elements we can find that mystery elements by defining with their colors.

Therefore, it is easy to identify some mystery elements because of their colors by looking at them.

answer; i do believe the correct answer is (river); /// good luck

there are no statements provided but here is why:

sulfur belongs to group 16 because it can be found in nature whether it is in a free or combined state.

hope this