Rank the following compounds in order of decreasing vapor pressure.
rank from highest to lowest vapor pressure

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

See the attachment and solve question 5th