Question

which is evidence that a chemical reaction has occurred?

a. a phase change occurs

b. a new gas is observed in the form
of bubbles

c. red and yellow paint mixing to make orange paint

d. the temperature of the substances remains constant

Answer 1

Answer:

b. a new gas is observed in the form  of bubbles

Explanation:

The only statement that was evidence of a chemical reaction is a new gas is observed in the form of bubbles Any time a new substance is created, a chemical reaction has taken place.