Question 18
A reaction that produces heat is an endothermic reaction.
False
(A reaction that produces heat is an exothermic reaction.)
Question 19
According to Newton's second law, what happens when the same force is applied to two objects of different masses?
a The object with greater mass will experience a smaller acceleration.
(According to Newton's second law, \( F = ma \), if the same force is applied, the acceleration is inversely proportional to the mass.)
Question 20
A radioisotope has a half-life of 7.5 hours. How many half-lives have occurred after 67.5 hours?
b 8 half-lives
(67.5 hours divided by 7.5 hours equals 9 half-lives.)