Solutions of NCERT Class XI Chemistry Chapter 2 Structure of Atom

(i) Calculate the number of electrons which will together weigh one gram. (ii) Calculate the mass and charge of one mole of electrons.

(i) Calculate the total number of electrons present in one mole of methane. (ii) Find (a) the total number and (b) the total mass of neutrons in 7 m . . .

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wavenumber (ν) of the yellow light.

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

A photon of wavelength 4 × 10-7 m strikes on metal surface, the work function of the metal being 2.13 eV. Calculate (i) the energy of the photo . . .

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in kJ mol-1.

A 25 watt bulb emits monochromatic yellow light of 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 frequen . . .

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level . . .

How much energy is required to ionise a H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of H atom ( en . . .

What is the maximum number of emission lines when the excited electron of a H atom in n = 6 drops to the ground state?

(i) The energy associated with the first orbit in the hydrogen atom is -2.18 × 10-18 J atom-1. What is the energy associated with the fifth orb . . .

Calculate the wavenumber for the longest wavelength transition in the Balmer series of atomic hydrogen.

Which of the following are isoelectronic species i.e., those having the same number of electrons? Na+, K+, Mg2+, Ca2+, S2-, Ar.

(i) Write the electronic configurations of the following ions: (a) H- (b) Na+ (c) O2- (d) F- (ii) What are the atomic numbers of elements whose oute . . .

What is the lowest value of n that allows g orbitals to exist?

An electron is in one of the 3d orbitals. Give the possible values of n, l and ml for this electron.

How many electrons in an atom may have the following quantum numbers? (a) n = 4, ms = - ½ (b) n = 3, l = 0

Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electro . . .

What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum ?

Calculate the energy required for the process He+ (g) → He2+ (g) + e- The ionization energy for the H atom in the ground state is 2.18 × 10-18 . . .

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 . . .

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

Calculate the wavelength for the emission transition if it starts from the orbit having radius 1.3225 nm and ends at 211.6 pm. Name the series to wh . . .

The bromine atom possesses 35 electrons. It contains 6 electrons in 2p orbital, 6 electrons in 3p orbital and 5 electron in 4p orbital. Which of the . . .

The unpaired electrons in Al and Si are present in 3p orbital. Which electrons will experience more effective nuclear charge from the nucleus ?

Indicate the number of unpaired electrons in : (a) P, (b) Si, (c) Cr, (d) Fe and (e) Kr.

(a) How many subshells are associated with n = 4 ? (b) How many electrons will be present in the subshells having ms value of -1/2 for n = 4

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 . . .