Question 3: PH is a measure of the number of in a water-based fluid. a. Hydrogen atoms B. hydrogen ions C. hydrogen molecules D. hydrogen bonds Question 4: a Is an attractive force between two Atoms (What is it?) Question 5: what property of water allows insects to walk on the surface? A period resistance to temperature change B. Expansion upon freezing C. Hi solubility D. Cohesion I’m sorry, these are all the points I have left. Please help me!

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

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

Abeaker of water was heated and then placed on a bench in the laboratory. the water cooled until it was the same temperature as the air in the laboratory. which of these explains the mechanism by which the water cooled? a. heat energy was transferred from the water to the air. b. water molecules from the water formed warm water currents. c. the water molecules absorbed energy from the molecules in the air. d. the water released radiation until it contained no heat energy.