Why are some isotopes used as tracers?

a. they leave visible trails.
b. they bind with all molecules.
c. they decay at a predictable rate.
d. they are uniquely identifiable like fingerprints.

Gymnast always perform on padded mats. how does the mats protect the gymnast

Explain what happens at the saturation point when adding salt to water at room temperature.

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?