Need help quickly practice problem

Q1) A spherical metallic shell of 40 cm diameter contains helium gas at a pressure of 1.5 atm. Temperature of the gas is 20 C. Atomic weight of Helium is 4. (Or molar mass is 4g/mole). Helium is a monatomic gas. a- How many moles of Helium are in the sphere, b- Calculate the total mass of the Helium gas inside the sphere. 0- Calculate the average translational kinetic energy of the Helium molecules. d- Calculate the total internal energy of the Helium molecules. e- Calculate the Vrms of the Helium molecules. f- In a constant-volume process (volume of the sphere remains constant), 300 J of heat added to the gas. Calculate the final temperature of the gas after the 300 J of heat is added to the gas. (Atomic mass unit (u) = 1.67x10'27 kg)