Question

Select all the correct answers.

Which of these events indicate that a chemical reaction might have occurred?
Silver jewelry becomes dark because of tarnish.
Water evaporates from salt water and leaves salt behind.
A liquid bubbles when heated.
A solid appears when two water-based solutions are added together.

Answer 1

Answer: I think the last one.

Explanation: Not 100% sure, but it would make the most sense.