Given the elements chlorine, iodine, oxygen, bromine, and fluorine, organize by increasing atomic size (atomic radius). Justify your response using your knowledge of periodic trends.

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

What is the percent by mass of oxygen in fe2o3

Select the correct location on the image identify the element that humans need to breathe. 2015 er r ights reserved