The Polarity of Water

Part A

Each water molecule is joined to _____ other water molecules by ____ bonds.

	two ... hydrogen
	two ... polar covalent
	four ... hydrogen
	four ... polar covalent
	three ... ionic

Correct

As can be seen in the illustration on page 1 of the activity titled "The Polarity of Water" a water molecule is joined to four other water molecules by hydrogen bonds.

Part B

The unequal sharing of electrons within a water molecule makes the water molecule _____.

	polar
	have a low surface tension
	hydrophobic
	ionic
	change easily from a liquid to gaseous form

Correct

The electrons spend more time with the oxygen of the water molecule than with the hydrogens of water. Thus, the oxygen has a net negative charge and the hydrogens have a net positive charge.

Part C

The tendency of an atom to pull electrons toward itself is referred to as its _____.

	polarity
	electronegativity
	covalency
	tonicity
	ionic potential

Correct

The question defines electronegativity.

Part D

In this molecule, what type of bond is found between the oxygen and hydrogens?

	nonpolar covalent
	hydrophobic
	hydrophilic
	ionic
	polar covalent

Correct

While oxygen shares electrons with hydrogen, the electrons spend more time with the oxygen than with the hydrogens.

Part E

Which of these bonds is weakest?

Correct

Hydrogen Bonds are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds because they involve the attraction of partial (not full) opposite charges.

Part F

Why isn't this insect drowning?

	It is difficult to change the temperature of water.
	The insect is very light.
	Surface tension.
	The insect is swimming.
	The insect is flying just above the water surface.

Correct

The high surface tension of water allows the insect to remain on the surface.