Chemistry Question Bank

[NEET 2021] A radio station broadcasts at frequency 1368 kHz. The wavelength of electromagnetic radiation emitted is (c = 3 × 10⁸ m/s)

[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?

Let mₚ be the mass of a proton, mₙ that of a neutron, M₁ that of a ²⁰₁₀Ne nucleus and M₂ that of a ⁴⁰₂₀Ca nucleus. Then

How long would it take a radiowave of frequency 6 × 10³ s⁻¹ to travel from Mars to Earth, a distance of 8 × 10⁷ km?

Suppose 10⁻¹⁷ J of light energy is needed by the interior of the human eye to see an object. The number of photons of green light (λ = 550 nm) needed to see the object are

A 4000 Å photon is used to break the I₂ molecule. The bond dissociation energy of I₂ is 246.5 kJ/mol. The % of photon energy converted to kinetic energy of iodine atoms is

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

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

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

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

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

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

[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] The total number of atomic orbitals in the fourth energy level of an atom is

[CBSE AIPMT 2011] If n = 6, the correct sequence of filling of electrons will be

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

[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?

[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

[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?

[VMMC 2010] Which of the following pairs is isoelectronic?

[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