How long would it take a radio wave with a frequency of 6.50 ✕ 108 hz to travel from mars to earth if the distance between the two planets is approximately 8.00 ✕ 107 km?

List four observations that indicate that a chemical reaction may be taking place

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm

Find the mass, in grams, of 5.00*10^23 molecules of f2