Question

Which of the following is a clue of a chemical change?

A. iron changes color when heated
B. gas bubbles form in boiling water
C. balls of wax form when melted wax is poured into ice water
D. a gas forms when vinegar and baking soda are mixed

Answer 1

The aswere is D.
Because its involve two material and causes reaction to make another form

Answer 2

The answer is D , when u mix the two ingredients it forms another by chemical reaction