How many neutrons does an element have if its atomic number is 42 and its mass number is 155? (10 points)

Llama have 74 chromosomes how many chromosomes will they be found in their gametes explain how you know

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.

What would happen to a volleyball left outside in the winter? o o o o a. it would expand. b. it would lose air. c. it would shrink. d. it would explode.