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)

Step-by-step solution

For hydrogen like species, from Bohr's formulas we get, r ∝ n 2 Z where n is orbit number, Z is atomic number Thus, ⇒ r He * = r H × n 2 Z ⇒ r He + = 0 . 6 × 3 2 2 = 2 . 7 Å = 270   ×   10 - 12   m ∴ r He + = 270 pm