1.25x10^28 atoms of oxygen equals how many moles? Please show work!

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

A1.5l container holds p.50 grams of an unknown gas at a pressure of 0.44 atm and a temperature of 50.c what is the molar mass of the unknown gas