What does H stand for in he periodic table of elements

What is the pressure of 0.500 moles of carbon dioxide gas in a 2.5 l tank and at a temperature of 301 k? (r=0.0821 l·atm/mol·k) 3.08 atm 1.2 atm 0.23 atm 4.01 atm 4.94 atm

Need , hurry pls create a superhero out of the element iron, what are its powers and his sidekick ( an element that works well with iron). how was the superhero made and who discovered him

How many more valence electrons does sodium need to have a full outer valence shell