[填空题]
In outer space the density ofxszka- tni7l:*r u8/jv2 jvw( matter is about one atom pea+cb0aw al2m so/kh. +r $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ = m/s $ \times10^{-22 }$ atm