[填空题]
(a) What is the average7qr8wsg* 5+nm kh j/qe tranzr8);t-r8 widu gu*g1klm g8mslational kinetic energy of an oxygen molecule at STP? gik8)1mdlu8z gt; rw8g -ru*m $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C? $ \times10^{3 }$ J