7. The number of atoms of oxygen in 3.7 moles of Al2(SO4)3 is: Anyone know how to get the answer? Thanks.

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line