Which describes how atoms form molecules. An atom is to a molecule as A. A letter is to a word
B. A cat is to a mouse
C. A spoon is to the soup
D. A book is to a page

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.