19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
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
The minimum frequency ν₀, below which the photoelectric effect is not observed, is called
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
The photoelectric effect shows:
[KCET 2012] The nitride ion in lithium nitride (Li₃N) is composed of
The kinetic energy of photoelectrons does NOT depend upon
Early Indian and Greek philosophers were of the view that 'A' are the fundamental building blocks of matter. Here, 'A' refers to
Increasing the frequency of incident radiation in the photoelectric effect increases the:
According to Bohr model, angular momentum of an electron in the 3rd orbit is
The smallest and lightest positive ion obtained from hydrogen is called
The oil drop experiment was developed by
Positive rays (canal rays) are:
Mass of neutron is about ________ times the mass of the electron.
In the hydrogen spectrum, the Balmer series lies in which region?
Atoms can be further divided into sub-particles like
Early Indian and Greek philosophers were of the view that 'A' are the fundamental building blocks of matter. Here, 'A' refers to
[NEET 2021] From the following pairs, which one is NOT an isoelectronic pair?
Pairing of electrons in orbitals belonging to the same subshell does not take place until each orbital is singly occupied. This is called
Pauli's exclusion principle states that
[NEET 2021] A radio station broadcasts at frequency 1368 kHz. The wavelength of electromagnetic radiation emitted is (c = 3 × 10⁸ m/s)
[NEET 2020] In ¹⁷⁵₇₁Lu, the number of protons, neutrons and electrons respectively are
[NEET 2016] Two electrons occupying the same orbital are distinguished by
[NEET 2016] How many electrons can fit in the orbital for which n = 3 and l = 1?
[CBSE AIPMT 2015] The orbital angular momentum of an electron in a d orbital is equal to