19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The relation between energy of radiation and its frequency was given by:
According to Planck, the smallest quantity of energy that can be emitted or absorbed in the form of electromagnetic radiation is called
The energy ratio of photons of wavelength 3000 Å and 6000 Å is
Einstein's theory of photoelectric effect is based on:
In the photoelectric effect, the number of photoelectrons emitted is proportional to:
Increasing the frequency of incident radiation in the photoelectric effect increases the:
The photoelectric effect shows:
The kinetic energy of photoelectrons does NOT depend upon
The minimum frequency ν₀, below which the photoelectric effect is not observed, is called
The energy of an electron in the 3rd orbit of hydrogen atom is
The Bohr orbit radius for hydrogen atom (n = 1) is 0.529 Å. The radius for the first excited state (n = 2) orbit is
According to Bohr model, angular momentum of an electron in the 3rd orbit is
Electronic energy is negative because
The value of a₀ (Bohr radius) in the expression for the radius of nth orbit of hydrogen atom (rₙ = n²a₀) is
Which of the following statements does NOT form a part of Bohr's model of hydrogen atom?
In the hydrogen spectrum, the Balmer series lies in which region?
Which series in the hydrogen spectrum lies in the ultraviolet region?
When electrons of a hydrogen atom return to the L shell (n=2) from higher energy shells, the series of lines formed is called
Bohr's theory is NOT applicable to:
A stream of electrons is passed between two charged plates at potential difference V (esu). If e and m are charge and mass of electron, the value of h/λ (λ = de Broglie wavelength) is
Early Indian and Greek philosophers were of the view that 'A' are the fundamental building blocks of matter. Here, 'A' refers to
Assertion (A): Atoms are electrically neutral. Reason (R): Number of protons and electrons are different in an atom.
Assertion (A): The radius of the first orbit of hydrogen atom is 0.529 Å. Reason (R): Radius of each circular orbit rₙ = 0.529 × (n²/Z) Å, where n = 1,2,3 and Z = atomic number.
Assertion (A): It is impossible to determine the exact position and exact momentum of an electron simultaneously. Reason (R): The path of an electron in an atom is clearly defined.
[Manipal 2008] Deflection of a few α-particles back on hitting a thin gold foil shows that