CHEMISTRY · Single correct · CBSE · Chemistry · Structure of Atom · Structure of Atom
Problem
For two ions in the same principal quantum state n=1, the radius of the orbit in He+ is smaller than that in H. Which statement best explains this observation?
(a) The larger nuclear mass of He+ shifts the centre of mass, forcing the electron to move in a tighter orbit.
(b) Because He+ lacks a second electron, there is no electron–electron repulsion, so the remaining electron collapses into a smaller orbit.
(c) Z for He+ is twice that of H, so the stronger Coulomb attraction pulls the n=1 electron closer to the nucleus.
(d) The electron in He+ carries extra kinetic energy and hence, by the de Broglie condition, occupies a smaller stationary orbit.