Which of the following is not a common sign of a possible chemical reaction?
a. dissolved precipitate
b. formation of bubbles
c. change in odor
d. warming or cooling

World class speed skaters can skate a 3,000-m course in about 4 minutes. what is their average speed for this course. a. 12.5m/s b. 1.33m/s c. 13.3m/s d. 1.25m/s

The illustration shown is an ovum, a female sex cell. a mutation in this cell may be passed to the woman’s offspring during a) birth. b) mitosis. c) dna replication. d) sexual reproduction

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one