How does atomic radius (size or atom diameter) affect bond distance (distance between atoms)?

Fill in the blanks for the following statements: the rms speed of the molecules in a sample of h2 gas at 300 k will be times larger than the rms speed of o2 molecules at the same temperature, and the ratio µrms (h2) / µrms (o2) with increasing temperature. a not enough information is given to answer this question b sixteen, will not change c four, will not change d four, will increase e sixteen, will decrease