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

a. freezing.

b. melting.

c. sublimation.

d. condensation.

Which of the following correctly identifies the composition of an oxygen atom? A. 8 protons, 8 electrons, and 8 neutrons B. 6 protons, 6 electrons, and 8 neutrons C. 8 protons, 6 electrons, and 7 neutrons D. 6 protons, 6 electrons, and 12 neutrons

What is the word equation for the reaction between magnesium oxide and hydrochloric acid

What is the angle between two of the nitrogen-hydrogen bonds in the ammonium (nh4) ion?

A flask at room temperature contains exactly equal amounts (moles of nitrogen and oxygen. a. which gas has the higher partial pressure? b. molecules of which gas have the higher average velocity? c.

We are interested in testing whether the variance of a population is significantly more than 625. The null hypothesis for this test is a. H0: σ2 ≤ 625. b. H0: σ2 > 625. c. H0: σ2 ≥ 625. d. H0: σ2 ≤ 25.

The average kinetic energy of the particles in a gas A. is not affected by the temperature of the substance. B. increases as the temperature of the substance decreases. C. is proportional to the temperature of the substance. D.

If the molar mass of NaCl is 58.44 g/mol, what amount of NaCl (in mol) is contained in 250.0 mg of NaCl?

Which has more surface area, a rock the size of your hand or a handful of small rocks?

4Al (s) + 3O2 (g) - >2Al2O3 (s) the reaction is started by mixing 10.0g of Al and 10.0g of O2. What is the limiting reaction and how much Al2O3 is produced?

F 3.84 moles of methane are consumed in this reaction, how many moles of HCN will be produced?