Hydrogen Bonds

A. Hydrogen bonds make liquid water cohesive

hydrogen bonds last only a few trillionths of a second

Cohesion- the tendency of molecules of the same kind to stick together

tress depend on cohesion because it helps transport water and nutrients from roots to their leaves by water beads

Adhesion- the clinging of one substance to another

surface tension- a measure of how difficult it is to stretch or break the surface of a liquid

hydrogen bonds give water the high surface tension

2.11

A. hydrogens bonding has a stronger resistance to temperature change than most other substances

Heat- amount of energy associated with the movement of atoms and molecules in a body of matter

Temperature- measures the average speed of molecules rather than the total amount of heat in a body of matter

B. heat must be absorbed in order to break hydrogen bonds, and heat is released when hydrogen bonds form

when water cools, more hydrogen bonds form, letting a lot of heat released

C. water’s resistance to temperature change also stabilizes ocean temperatures, creating a favorable environment for marine life

66% of your body weight is water

D.

evaporative cooling- when a substance evaporates, the surface of the liquid that remains behind cools down

this occurs because the molecules with the greatest energy( hot molecules) leave

this prevents land animals from overheating

2.12

A. ice is less dense than liquid water

as it freezes, each molecule forms a stable bond with its neighbors, holding them at arms length and creating a 3D crystal

since ice has its molecules spread apart, the ice becomes less dense because the molecules are