Density of kcl the crystal structure of kcl is the same as that of naci, as shown in figure 3 of the notes on crystal structure (shackelford fig. 3.9, p 67). the density of kcl is 1.984 mg/m3 (g/cm3) a. what are the electronic structures of the k* and cl ions? b. what is the distance between the centers of neighboring potassium and chlorine ions? c. compare your answer in part (b) to what would be estimated from appendix two in shackelford; cl: atomic number k: atomic number 19; atomic radius 0.231 nm; ionic radius 0.133 nm nm; ionic radius 0.181 nm 17: atomic radius 0.107

Silica, sio2, is formed on silicon as an electrically insulating layer for microelectronic devices. silica is formed when silicon is exposed to o2 gas at an elevated temperature. at 900˚c, it takes 90 minutes for the oxygen to diffuse from the surface to form a 0.06 micron (0.06 x 10-6 m) thick layer of sio2 on

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d