We blow up a balloon from 5 Liters to 10 Liters and tie it off. Then we pass out from lack of oxygen. The balloon initially had 18 mol of CO2, how many moles of CO2 are in the balloon at the end? It is not 9!

What type of energy conversion occurs when you place your feet near the fire place and they become warm

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?

The molar mass of iron(fe) is 55.8 g/mol. what is the mass in grams of 2.25 moles of iron?