Assume that the radius of the first Bohr orbit of hydrogen atom is 0.6 Å. The radius of the third Bohr orbit of He+ is _______ picometer. (Nearest integer) [2023]
(270)
rn=r0n2Z
(r1)H=r0(1)21=0.6Å
(r3)He+=r0n2Z
=0.6(32)2=0.6×92=2.7Å=270 picometer.