A student applies the Bohr formula to calculate the radius of the first orbit ( ) of…
CHEMISTRY · Single correct · CBSE · Chemistry · Structure of Atom · Structure of Atom
Problem
A student applies the Bohr formula rn=Zn2a0 to calculate the radius of the first orbit (n=1) of neutral lithium (Z=3) and obtains 0.59×10−10m. Which of the following best explains why this value disagrees with the experimentally measured atomic size of lithium?
(a) The Bohr formula is valid only when Z=1; applying it to Z=3 violates its derivation
(b) The model ignores the repulsive forces between the two inner electrons and the outer electron
(c) The predicted radius cannot be compared with measurements because experiments quote the much larger van-der-Waals radius
(d) The model treats the electron strictly as a classical particle and ignores its de-Broglie wave nature, leading to an incorrect size