What type of bond joins the carbon atom to each of the hydrogen atoms?

[image]

single (nonpolar) covalent

Hydrogen bonding is most often seen _____.     

a)when the bonds within the molecule are nonpolar covalent bonds

b)if the molecule consists of three or fewer atoms        

c)when multiple carbon atoms are present        

d)when hydrogen is covalently bonded to an electronegative atom

e)in molecules whose three-dimensional shape is tetrahedral        

d)when hydrogen is covalently bonded to an electronegative atom

b)Van der Waals interactions can form between atoms of equal electronegativity.

Which statement about weak bonds is correct?

a)Weak bonds are transient and easily reversible. 

b)Weak chemical bonds form only between atoms of similar electronegativity.

c)Weak bonds are less important to living things than strong covalent bonds.

a)Weak bonds are transient and easily reversible. 

nonpolar covalent bond

Atoms with similar electronegativities form nonpolar covalent bonds

know:

[image]

know:

[image]

What type of bond is joining the two hydrogen atoms?

[image]

covalent

water’s high heat of vaporization

Which property of water molecules allows an animal to cool itself by sweating?

[image]

a b and c

Random collisions allow some molecules to accumulate more energy than other molecules. The weakness of hydrogen bonds lets those molecules escape, leaving the cooler molecules behind.

it takes energy to break hydrogen bonds.

Correct! At boiling, all the added heat is used to break hydrogen bonds. Free of the water mass, the departing steam carries away all the added energy, with none left over to raise the temperature.

Which statement helps to explain why ice is less dense than liquid water?

[image]

a and b

Why doesn't oil mix with water?

[image]

(c) Polar molecules attract one another.