Question

unit 1, lc2 practice
which of these is not evidence that a chemical reaction has taken place?
○ fizzing
○ color change
○ temperature change
○ solids dissolving in liquid

Explanation:

• Fizzing indicates gas production (a new substance), which is a sign of a chemical reaction.
• Color change often means new substances with different properties are formed, a chemical reaction indicator.
• Temperature change (exothermic or endothermic) shows energy changes associated with chemical reactions.
• Solids dissolving in liquid is a physical change (like dissolving salt in water), no new substances are formed.

Answer:

solids dissolving in liquid