How do you know what direction the
air masses are moving?

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.