Biology 2.2 - Properties of Water

What two elements make up water?

• Helium and oxygen

• Hydrogen and oxygen

• helium and carbon

A water strider can skate along the top of a pond because:

• covalent bonds result in water cohesion

• hydrogen bonds result in water cohesion (surface tension)

• water striders have adapted to take advantage of water cohesion

What word describes when water is attracted to other substances?

• adhesion

• cohesion

• surface tension

Why can water have no net charge but have slight charges in different parts of the molecule?

• The oxygen end is slightly negative and the hydrogen end is slightly positive

• The hydrogen end is slightly negative and the oxygen end is slightly positive

• The hydrogen and oxygen ends change in polarity

The weak attractions between water molecules are called

• Covalent bonds

• Ionic bonds

• Hydrogen bonds

Water’s attraction to other water molecules

• adhesion

• capillary action

• cohesion

Which is NOT a unique property of water?

• Frozen water floats on liquid water.

• Water covers most of the Earth’s surface and retains a large amount of heat.

• Water cools very rapidly.

Water is polar because...

• The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms.

• The molecule has two poles, at which the it is colder than other regions of the molecule.

• The unequal sharing of electrons gives the water molecule a slight negative charge near its hydrogen atoms and a slight positive charge near its oxygen atom.

Tendency of molecules of the same kind to stick to one another

• cohesion

• adhesion

• solution

Molecule in which opposite ends have opposite electric charges

• cohesion

• polar molecule

• hydrogen bond