The cell reaction for a lead storage battery (car batteries, etc.) is: E° = 1.92 V. Pb(s) + PbO2(s) + 2 H+(aq) + 2HSO4-(aq)-->2PbSO4(s) + 2H2O (l) To provide a potential of around 12.6 V, how many cells would be needed?

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.