How many grams are in 0.21mol sample of ethyl alcohol?

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

Which best describes how johannes kepler developed his laws of planetary motion

Name the element in group 17, period 2. (periodic table)