Dennie wanted to see if crayfish preferred one kind of food over another. He gave one group of crayfish plants, both living and dead, to eat. He gave the other group insects, living and dead, to eat. What is the independent variable in Dennie's experiment? a)type of food b)weight of crayfish c)typeof water used d)age of crayfish

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds

a electronegativity decreases beacuse the size of nucleus is bigger.

it is b that is the answer.