19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
As an electron moves away from the nucleus, its potential energy
[NEET 2022] If the radius of the second Bohr orbit of He⁺ ion is 105.8 pm, what is the radius of the third Bohr orbit of Li²⁺ ion?
[NEET 2014] Calculate the energy in joule corresponding to light of wavelength 45 nm. (h = 6.63 × 10⁻³⁴ Js, c = 3 × 10⁸ ms⁻¹)
[Kerala CEE 2014] The maximum number of electrons that can be held by a subshell with azimuthal quantum number 'l' in an atom is given by
[CBSE AIPMT 2013] Based on equation E = −2.178 × 10⁻¹⁸ J × Z²/n², which of the following is NOT correct?
[NEET 2013] Planck's constant h = 6.63 × 10⁻³⁴ Js. Speed of light c = 3 × 10¹⁷ nm/s. Which value is closest to the wavelength (in nm) of a quantum of light with frequency 6 × 10¹⁵ s⁻¹?
[CBSE AIPMT 2011] The energies E₁ and E₂ of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths λ₁ and λ₂ will be
[CBSE AIPMT 2011] If n = 6, the correct sequence of filling of electrons will be
[KCET 2010] The wave number of a spectral line in the emission spectrum of hydrogen will be equal to (8/9)R_H if the electron jumps from
[AMU 2010] When the electron of a hydrogen atom jumps from n = 4 to n = 1 state, the number of spectral lines emitted is
[CBSE AIPMT 2009] Which of the following is NOT a permissible arrangement of electrons in an atom?
[Manipal 2009] The uncertainty in position of an electron (m = 9.1 × 10⁻²⁸ g) moving with velocity 3.0 × 10⁴ cm s⁻¹ accurate to 0.011% will be (h = 6.626 × 10⁻²⁷ erg·s)
[AMU 2009] The radius of the Bohr orbit of the H-atom is r. Then the radius of the first orbit of Li²⁺ will be
[Haryana PMT 2009] The number of radial nodes of 3s and 2p-orbitals are respectively
[CBSE AIPMT 2008] If uncertainty in position and momentum are equal, then uncertainty in velocity is
Assertion (A): For Balmer series of hydrogen spectrum, the value of n₁ = 2 and n₂ = 3, 4, 5 ... Reason (R): The value of n for a line in Balmer series having the highest wavelength is n₁=4 and n₂=6.
The number of unpaired d-electrons retained in Fe²⁺ ion (At. no. of Fe = 26) is
The correct set of four quantum numbers for the valence electron of rubidium (Z = 37) is
Which of the following electronic transitions in a hydrogen atom will require the largest amount of energy?
The most probable radius (in pm) for finding the electron in He⁺ is
The velocity of an electron in the second shell of hydrogen atom is
For a Bohr atom, angular momentum of the electron is (n = 1, 2, 3 …)
According to Bohr's theory, the angular momentum of an electron in 5th orbit is
Energy of electron of hydrogen atom in the second Bohr orbit is
The ionization energy of H atom is 13.6 eV. The ionization energy of Li²⁺ ion will be