Helium is used to fill a balloon of diameter 50 cm at 30 C and 2 atm. The mass of a helium atom is 4.0026 u, the universal gas constant id 8.31451 J/K mol, Boltzmann's constant is 1.38066 x 10-23 J/K, and Avogadro's num- ber is 6.022 x 1023 1/mol. 1.66 x 10 2 kg = 1 u, and 101300 Pa = 1 Pa. How many helium atoms are there in the balloon? Question 10, chap 121, sect 1. part 2 of 3 10 points What is the average kinetic energy of each helium atom? Answer in units of J