Answer the following questions in the space provided. 1. Classify each of the following as a homogeneous or heterogeneous substance.
a. iron ore
b. quartz
c. granite
d. energy drink
e. oil-and-vinegar salad dressing
f. salt
g. rainwater
h. nitrogen
2. Classify each of the following as a physical or chemical change.
a. ice melting
b. paper burning
c. metal rusting
d. gas pressure increasing
e. liquid evaporating
f. food digesting
3. Compare a physical change with a chemical change.

iron ore is heter

quartz homo

granite heter

energy drink homo

oil-and vingar salad dressing heter

salt homo

rainwater homo

nitrogen homo

ice melting chemical

burning paper chemical change

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.