Write a note on Thomson's plum pudding model of an atom.

What did Rutherford's alpha ray scattering experiment prove

What are the defects of Rutherford's model?

What is the charge and mass of an electron?

What is the difference between atomic mass and mass number?

Give the number of electrons in the following species. H₂ , H₂ , O₂ and O_2^- 

How many neutrons and protons are there in the Following nuclei?
\(_{ 6 }^{ 13 }{ C }\),\(_{ 2 }^{ 18 }{ O }\).\(_{ 12}^{ 24}{ Mg }\),\(_{26 }^{ 56}{ Fe }\),\(_{ 88}^{ 38}{ Sr }\)

After the execution of the \(\alpha\)-ray scattering experiment, what were the observations made by Rutherford? What did he conclude from his observations?

Write the values of all the four quantum numbers for all the electrons present in hydrogen and Helium atoms.

Write the values of four quantum numbers present in the last electron in, an atom having the electronic configuration
(i) 1s² 2s² 2p¹ 
(ii) 1s² 2s² 2p⁶ 3s² 3p².

How many electrons are present in all subshells (fully filled) with n + l = 5?

Why Pauli exclusion principle is called exclusion principle?

At what distance is the radial probability maximum for 1s orbital? What is this distance called?

Bring out the similarities and dissimilarities between a 1s and 2s orbital.

How many radial f spherical nodes will be present in 5f orbital?

For each of the following pair of hydrogen orbitals indicate which is higher in energy?
(i) 1s, 2s
(ii) 2p, 3p
(iii) 3d_xy 3d_yz
(iv) 3s, 3d
(v) 4f, 5s.

How many electrons in sulphur (z = 16) can have n + 1 = 3?

The ground state electronic configurations listed below here are incorrect. Explain what mistakes have been made in each and correct the electronic configuration.
(i) Al = 1s² 2s² 2p⁴ 3s² 3p⁶ .
(ii) B = 1s² 2s² 2p⁵
(iii) F = 1s² 2s² 2p⁵.

What is the angular momentum of an electron in
(i) 2s orbital
(ii) 4f orbital?

Draw the shapes (boundary surfaces) for the following orbitals.
(i) 2p_x
(ii) 3d_z2 
(iii) 3d_x2_y2

Chromium (Z = - 24) and copper (Z = 29), should have the configuration.
Cr = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴ 4s²
Cu = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁹ 4s²
But their actual configuration are Cr = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹ and
 Cu = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹ Explain the reason.

Calculate the wave length of an electron (mass = 9.1 x 10^-31 kg) moving with 'a velocity of 10³ ms^-1 (h = 6.6 x 10^-34 kg m² sec^-1).

The kinetic energy of a subatomic particle is 5.58 x 10^-25 J. Calculate the frequency of the particle wave. (Planck's constant h = 6.626 x 10^-34 kg m² s^-1)

A microscope using suitable photons is employed to locate an electron in an atom within a distance of 0.1\(\overset { o }{ A } \)  What is the uncertainty involved in the measurement of its velocity.

Energy of an electron in hydrogen atom in ground state is -13.6 eV. What is the energy of the electron in the second excited state?