Which identifies that a chemical reaction has occurred?

A.
New substances are produced.

B.
The color has changed.

C.
Bubbles have formed.

D.
Temperature has changed.

Question

Which identifies that a chemical reaction has occurred?	
 
 A.
New substances are produced.
 
 B.
The color has changed.
 
 C.
Bubbles have formed.
 
 D.
Temperature has changed.

anonymous · Answer

Temperature could change from other sources of heat than reaction.
Bubbles could occur due to trapped gas coming out.

You are down to A or B. Which one indicates reactants have become products?

anonymous · Answer

Adding to what Douglas said, it can not be color change because when you crack an egg, it starts clear with a little yellow, but if you mix it then it turns all yellow, which is a physical change and not chemical, a chemical reaction will completely change the substance rather then the look of the object. With makes the answer A. new substances are produced.

fantalux · Answer

Thankyou.

anonymous · Answer

Bie ke qi! (Chinese for you're welcome)