Lena later copied the title of the notes from a friend what title did lena most likely copy

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.

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.