What is the experimental evidence in support of the idea that electronic energies in an atom are quantised?

Which two discoveries put strong challenge to the Bohr model?

The magnitude of charge on the electron is \(4.8\times { 10 }^{ -10 }\) esu. What is the charge on the nucleus of a helium atom?

What physical meaning is attributed to the square of the absolute value of wave function \(|\psi |^{ 2 }\)?

An electron is in one of the 3d orbitals. Give the possible values of n, l and ml for this electron.

What is the lowest value of n that allows g orbitals to exist?

Why does the charge to mass ratio of positive rays depend on the residual gas in the discharge tube? Why is the charge to mass ratio of all cathode rays are same?

Calculate energy of one mole of photons of radiation whose frequency is 5 x 10¹⁴ HZ.

What kind of information about an electron in an atom is obtained from its wave function?

According to de-Broglie, matter should exhibit dual behaviour, that is both particle and wave like properties.However, a cricket ball of mass 100g does not move like a wave when it is thrown by a bowler at a speed of 100km/h.Calculate the wavelength of the ball and explain why it does not show wave nature?

Correct the following electronics configuration of the elements in the ground state.
(i) \({ 1s }^{ 2 }2s^{ 1 },{ 2p }_{ x }^{ 2 },{ 2p }_{ y }^{ 2 },{ 2p }_{ z }^{ 2 },3s^{ 2 },{ 3p }_{ x }^{ 1 }\)
(ii) \({ 1s }^{ 2 }2s^{ 1 },{ 2p }_{ x }^{ 1 },{ 2p }_{ y }^{ 1 },{ 2p }_{ z }^{ 1 }\)
(iii) \({ 1s }^{ 2 }2s^{ 2 },{ 2p }^{ 6 },3s^{ 2 },{ 3p }^{ 6 },3d^{ 5 }\)
(iv) \({ 1s }^{ 2 }2s^{ 2 },{ 2p }^{ 6 },3s^{ 2 },{ 3p }^{ 6 },3d^{ 4 },4s^{ 2 }\)

The arrangement of orbitals on the basis of energy is based upon their (n + 1), lower is the energy. For orbitals having same values of (n + l), the orbitals with lower value of n will have lower energy.
Based upon the above information, solve the questions given below.
a) Which of the following orbitals has the lowest energy?
4d, 4f, 5s, 5p
b) Which of the following orbitals has the highest energy?
5p, 5d, 5f, 6s, 6p

If the velocity of the electron in Bohr's first orbit is 2.19 x 10⁶ ms^-1 , calculate the de-Broglie wavelength associated with it.

A beam of helium of atoms move with a velocity of \(2.0\times { 10 }^{ 3 }{ ms }^{ -1 }\) Find the wavelength of the particle constituting the beam. (h = 6.626 \(\times \)10^-34 Js).