PLS HELP i will give 10 points In Mendeleev’s Periodic Table, why was there no mention of Noble gases like Helium, Neon and Argon?

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced. be sure your answer has the correct number of significant digits.

Ineed this asap part i: scientific method what is the difference between science and pseudoscience? what is the scientific method?