How much pressure is exerted by a sample of gas at 85.0 °C if the same volume exerts a pressure of 1.00 atmospheres at a temperature of 20.0 °C? I'm pretty sure this is a Combined law question but not so sure, I have other questions with other laws but I am mostly stuck on the Combined Laws.
I'm not the best at mathematics so can someone please lead me in the right direction for these, it would be greatly appreciated, thanks :)

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Darla claims that the first periodic table developed by mendeleev was not completely accurate, so it is not useful at all. harmony argues that it establish the periodic table we use today, making it more credible. who is correct and why? darla is correct, because a model that has any mistakes should be thrown out. darla is correct, because a good model would not need to change. harmony is correct, because mendeleev’s model had all of the information correct in the first version. harmony is correct, because mendeleev’s model made predictions that came true.

What is avogadro’s number, and why is it useful