In which direction does heat energy move? (2 points) a
From cold objects to colder objects

b
From colder objects to warmer ones

c
From warmer objects to colder ones

d
From warm objects to warmer objects

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.