Calculate the mass of 0.25 mole of carbon dioxide​

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. one of these isomers has a heat of hydrogenation of 101 kj/mol (24.1 kcal/mol), and the heat of hydrogenation of the other is 113 kj/mol (27.1 kcal/mol). match the heat of hydrogenation with the appropriate dihydronaphthalene.

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom