• # question_answer The ratio between radii of $H{{e}^{+}}$ ion and H atom is [MP PET 1996] A) $\frac{1}{2}$ B) 1 C) $\frac{3}{2}$ D) 2

Value of Z  for hydrogen =1 Value of Z  for helium = 2 Value of n for both is = 1 ${{r}_{H}}=\frac{0.52\times {{1}^{2}}}{1}$  ${{r}_{H{{e}^{+}}}}=\frac{0.52\times {{1}^{2}}}{1}$ $\frac{{{r}_{H}}}{{{r}_{H{{e}^{+}}}}}=1:1$ or ${{r}_{H{{e}^{+}}}}:{{r}_{H}}=1:1$