PLEASE HELP ME A 450 ml gas sample has a pressure of 1.25 atm at 65 °C. What is the temperature, in °C, at which the gas will expand to 865 mL with a pressure of 0.89 atm?

And a) oxygen i believe

So the main goal for the elements is stability which is a complete/full valence shell and typically the magic number for a stable element is 8 valence electron but not always. so elements to the left of the periodic table tend to be way less stable then those on the right, so the elements on the left are much more reactive.