What are some observations we can make to determine if something has energy?

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.

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

What volume of argon gas is equal to 1.60 grams of argon