A small cup of water is left out on the counter. Three days later, the water is gone. Which phase change describes what has occurred?

Melting

Sublimation

Evaporation

Condensation

Which substances have the same empirical formula and why?

phosphorus 32 has a half life of 14.3 days how much of a 4 mg sample of phosphuros 32 will remain after 71.5 days

Name 5 elements that we don't know what the state is at room temperature

What is the radioactive nucleus before it decays

Which of these is a compound? A. Steel B. Suger C. Air D. Nitrogen

4fe (s) + 3o2 (g) →2fe2o3 (s) how many grams of Fe2O3 are produced when 12.0 of iron rusts

Chromium 6 is commonly referred to as?

How does a parallel circuit differ from a series circuit? A. A parallel circuit had one path for electrons, but a series circuit has more then one path. B. A series circuit has one path for electrons, but a parallel circuit has more then one path. C.

Which of the following is an example of potential energy? -none of the above -A person jumping on a trampoline -a book on the shelf -A person running in place

One atom of silicon can properly be combined in a compound with a. three atoms of hydrogen. b. four atoms of calcium. c. two atoms of oxygen. d. one atom of chlorine.