Which of the following is not a compound?
Cl
CO2
NaCl
HCl​

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

What is the empirical formula for c4h8o2

The sum of the oxidation numbers in a neutral compound is always