Which of the following statements is true? A. In rarefactions, particles in a sound wave are spread far apart.
B. The height of a wave determines the loudness of a sound.
C. The higher the frequency of a sound, the higher the pitch.
D. All of the above.

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Calculate the number of molecules present in 0.750 mol of mgo.

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?