An experiment is performed in which a crystalline substance is added to a beaker filled with room-temperature water. The following observations were made: 1. The crystals dissolve.
2. A precipitate forms.
3. The bottom of the beaker feels warm to the touch.
4. Bubbles begin to form in the water.
Which observations are evidence that a chemical reaction took place?
Give a explanation.

Explanation:

I think it is a precipitate because that is when two solutions react to make a solid. I am not sure of this answer, however, so please correct me if I am wrong. Everybody makes mistakes sometimes. Hope this helped!

if im not mistaken its a. collective emotional arousal

the following men who did not in the unification of italy were.

a) giuseppe mazzini

c) alexander ll

the other two men were camilo cavour and giuseppe garibaldi they the unification of italy by yielding territories in the italian unification. in 1861 italy was declared a united-nation state under the sardinian king victor immanuel ll.