All chromatography experiments require both a stationary phase and mobile phase. in this thin -layer chromatography experiment, which is the stationary phase?

a) a
b) b
c) c
d) d

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

Write a paragraph that provides examples of each stage of volcanic activity, a description of the volcano, and facts about each stage.

Neils bohr believed that electrons orbited the nucleus in different energy levels, based on strong support from