19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The ratio of the energy difference between the 1st and 2nd Bohr orbits to that between the 2nd and 3rd Bohr orbits is
According to Bohr's theory, the angular momentum of an electron in 5th orbit is
[NEET 2019] Orbital having 3 angular nodes and 3 total nodes is
[CBSE AIPMT 2013] Based on equation E = −2.178 × 10⁻¹⁸ J × Z²/n², which of the following is NOT correct?
The ratio of the energy difference between the 1st and 2nd Bohr orbits to that between the 2nd and 3rd Bohr orbits 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
If the threshold frequency of a metal for the photoelectric effect is ν₀, which of the following will NOT happen?
The threshold wavelength for the photoelectric effect on sodium is 5000 Å. Its work function is:
Ultraviolet light of 6.2 eV falls on an aluminium surface (work function = 4.2 eV). The kinetic energy (in joule) of the fastest electron emitted is approximately:
The energy required to break one mole of Cl–Cl bonds in Cl₂ is 242 kJ mol⁻¹. The largest wavelength of light capable of breaking a single Cl–Cl bond is
The number of photons emitted in 10 hours by a 60 W sodium lamp (λ = 6000 Å) is approximately
The number of photons of light with wave number ν̄ = 2.5 × 10⁶ m⁻¹ necessary to provide 1 J of energy are
Which is NOT a characteristic of Planck's quantum theory of radiation?
Calculate the frequency of yellow radiation having wavelength 5800 Å.
Rutherford's nuclear model of the atom failed to explain
In the Rutherford scattering experiment, most α-particles passed straight through the gold foil because
The electrical discharge through gases could be observed only at
The e/m ratio for anode rays (positive rays) in comparison to cathode rays is:
[NEET 2019] 4d, 5p, 5f and 6p orbitals are arranged in order of decreasing energy. The correct option is
[NEET 2019] Orbital having 3 angular nodes and 3 total nodes is
[CBSE AIPMT 2015] The number of d-electrons in Fe²⁺ (Z = 26) is NOT equal to the number of electrons in which one of the following?
The correct order of increasing energy of orbitals in hydrogen atom is
Aufbau principle does NOT give the correct arrangement of filling of atomic orbitals in
The correct ground state electronic configuration of chromium atom (Z = 24) is