Chemistry Question Bank

A photon of 300 nm is absorbed by a gas and then re-emits two photons. One re-emitted photon has wavelength 496 nm. The wavelength of the second re-emitted photon is

A 20 W light source emits monochromatic light of wavelength 600 nm. The number of photons ejected per second expressed in terms of Avogadro's constant N_Av is approximately

[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?

[AIPMT 2012] Maximum number of electrons in a subshell with l = 3 and n = 4 is

[KCET 2012] The nitride ion in lithium nitride (Li₃N) is composed of

[Manipal 2010] Which one of the following statements in relation to the hydrogen atom is correct?

As an electron moves away from the nucleus, its potential energy

If a certain metal is irradiated with two different light radiations of frequency x and 2x, the maximum kinetic energies of ejected electrons are y and 3y respectively. The threshold frequency of the metal will be

When sodium compounds are heated in a Bunsen burner flame, they emit light at 5890 Å. If 1.0 × 10⁻⁴ moles of sodium atoms each emit one photon of this wavelength, how much energy (in kJ) is emitted?

Find the frequency of light that corresponds to photons of energy 5.0 × 10⁻⁵ erg

[NEET 2013] What is the maximum number of electrons that can be associated with the quantum numbers n=3, l=1 and m=−1?

[CBSE AIPMT 2013] Based on equation E = −2.178 × 10⁻¹⁸ J × Z²/n², which of the following is NOT correct?

[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

[Kerala CEE 2014] The ratio of de Broglie wavelengths of a deuterium atom to that of an α-particle, when the velocity of deuterium is five times that of the α-particle, is

[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)

[CBSE AIPMT 2015] The orbital angular momentum of an electron in a d orbital is equal to

[NEET 2016] How many electrons can fit in the orbital for which n = 3 and l = 1?

The correct ground state electronic configuration of chromium atom (Z = 24) is

In the H–He⁺ mixture experiment, the ratio of potential energy of the n=2 electron for the H atom to that of He⁺ ion is

In the H–He⁺ mixture experiment, the wavelength of light emitted in the visible region by He⁺ ions after collisions with H atoms is

[MP PMT 2010] The relation between wave nature of light (photons) and stream of particles is given by de Broglie's equation:

Which is NOT a characteristic of Planck's quantum theory of radiation?

According to Planck, the smallest quantity of energy that can be emitted or absorbed in the form of electromagnetic radiation is called

The number of photons of light with wave number ν̄ = 2.5 × 10⁶ m⁻¹ necessary to provide 1 J of energy are

The number of photons emitted in 10 hours by a 60 W sodium lamp (λ = 6000 Å) is approximately