Which field of science studies the composition and structure of matter

What is the molecular weight of copper

Achemist reacted 57.50 grams of sodium metal with an excess amount of chlorine gas. the chemical reaction that occurred is shown. na + cl2 → nacl if the percentage yield of the reaction is 86%, what is the actual yield? show your work, including the use of stoichiometric calculations and conversion factors.

How many moles of an ideal gas would occupy a 25.0 liter container when the temperature is 295 k and the pressure is 0.850 atm?