A cation with a +4 charge has 26 neutrons and 18 electrons. What is the identity of the element?

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

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

8) warming your hands by a fire is an example if which heat transfer? a. conduction b. convection c. radiation d. none of these