Hydrogen Atom: What Is the Radius of the Smallest Electron

Multiple Choice

Hydrogen atom: What is the radius of the smallest electron orbit in a singly-ionized helium atom?

A) 1.32 × 10^-11 m
B) 2.65 × 10^-11 m
C) 5.29 × 10^-11 m
D) 1.06 × 10^-10 m