Explain early attempts at organizing the elements, what Mendeleev's basis was for his organization of the elements, and how early versions of the periodic table compare with the modern version.

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

Type the correct answer in the box. spell all words correctly. what is the correct term for living the most sustainable life you can within your current circumstances? when your are being as sustainable as you can within your current lifestyle, you are said to be sustainability.

Over the last 90 years, scientists have added to the body of evidence supporting the big bang theory. what is the latest piece of evidence discovered in 2014?