The phase change in which a substance changes from a solid to a liquid is

a. freezing.

b. melting.

c. sublimation.

d. condensation.

The density of gas particles in a section of Earth's atmosphere decreases. Which of the following is the most likely explanation for this event?

Suppose it is the night before before a big parade, and you are in charge of inflating the big parade balloons. You just learned that the temperature will rise 15 degrees C between early morning and the time the parade starts.

The combined gas law relates which of the following?

2KHCO3 (s)  K2CO3 (s) + CO2 (g) + H2O (l) How many moles of potassium carbonate will be produced if 454 g of potassium hydrogen carbonate are heated? A) 2.27 mol B) 3.29 mol C) 11.4 mol D) 227 mol E) 4.54 mol

What determines wether or not a reaction is spontaneous answers?

The density of aluminum is 2.70g/cm^3. a piece of aluminum foil has a volume of 54.0 cm^3. what is the mass of this piece of aluminum foil?

Describe how the atoms in Calcium Chloride obey the octet rule.

How many milliliters of 2.55M NaOH is needed to make 125mL of 0.75M NaOH solution?

2. What type of bond holds together nitrogen atoms? a. Single Bond b. Double Bond c. Triple Bond d. no bonds hold nitrogen together

Charge on monatomic ions: a) I b) Sr c) K d) N e) S f) In