Why is Hund’s rule called rule of maximum multiplicity?

What are the postulates of nuclear model of atomic structure according to Rutherford's α-particle scattering experiment? Point out it's limitation.

What are the conclusions by Rutherford's from his α-ray scattering experiment about the structure of atom? Mention its limitation.

Write down the essential postulates of Bohr's model of an atom. How did it explain the stability of an atom?

Write down the essential postulates of Bohr's model of an atom. How does this model correct the defect of Rutherford's atomic model?

Does Bohr's theory explain the origin of hydrogen spectra? Name the different spectral lines with labeled diagram.

How does Bohr's theory explain the origin of hydrogen spectra? Name the various Spectral Series observed in the atomic spectrum of hydrogen with a well labeled diagram.

Why does hydrogen atom produce so many spectral lines even though it contains one electron? Draw a well-label diagram to explain the various spectral series observed in it.

Explain main postulates of Bohr’s theory of atomic model. How did this theory justify the origin of spectral lines in hydrogen atom?

What are quantum number? An atom has 20 electrons. Find out:

1. Its atomic numbers and total number of p-electron.
2. The value of Azimuthal quantum number (l) and magnetic quantum number (m) of the 19th electrons of the atom.
3. Its group position in the periodic table.

Ans: (i) 20 and 12 (ii) l = 0 (iii) m = 0

Define Aufbau Principle. An atom has 2 electrons in first (K) shell, 8 electrons in second (L) shell and 2 in third (M) shell. If so, find out the following:

1. Electronic configuration of the atom.
2. Total number of principles quantum numbers.
3. Total number of sub-shells.
4. Total number of s-electrons.

Ans: (a) 1s² 2s² 2p⁶ 3s² (b) 3 (c) 2 (d) 6

What are the differences between an atomic orbit and an atomic orbital? Draw the shapes of s and p orbital?