Science (English Medium) इयत्ता ११ - CBSE Question Bank Solutions

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number (`bar v`) of the yellow light.

Find energy of each of the photons which correspond to light of frequency 3 × 10¹⁵ Hz.

Find energy of each of the photons which have the wavelength of 0.50 Å.

What is the number of photons of light with a wavelength of 4000 pm that provide 1 J of energy?

A photon of wavelength 4 × 10^–7 m strikes on the metal surface, the work function of the metal being 2.13 eV. Calculate

1. the energy of the photon (eV),
2. the kinetic energy of the emission, and
3. the velocity of the photoelectron (1 eV = 1.6020 × 10^–19 J).

A 25-watt bulb emits monochromatic yellow light of the wavelength of 0.57μm. Calculate the rate of emission of quanta per second.

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency (v₀) and work function (W₀) of the metal.

Following results are observed when sodium metal is irradiated with different wavelengths. Calculate (a) threshold wavelength and, (b) Planck’s constant.

The electron energy in the hydrogen atom is given by E_n = (–2.18 × 10^–18)/n² J. Calculate the energy required to remove an electron completely from the n = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?

An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the atomic symbol.

An ion with mass number 37 possesses one unit of negative charge. If the ion contains 11.1% more neutrons than the electrons, find the symbol of the ion.

An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.

In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of 3.15 × 10^–18 J from the radiations of 600 nm, calculate the number of photons received by the detector.

The work function for caesium atom is 1.9 eV. Calculate

1. the threshold wavelength and
2. the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength 500 nm, calculate the kinetic energy and the velocity of the ejected photoelectron.

The ejection of the photoelectron from the silver metal in the photoelectric effect experiment can be stopped by applying the voltage of 0.35 V when the radiation 256.7 nm is used. Calculate the work function for silver metal.

What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm³ flask at 27 °C ?

A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

C₆H₅OH 

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

C₆H₅NO₂ 

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

CH₃CH = CHCHO