Solution of Chapter 2. Structure of Atom (Chemistry - Exemplar Book)

Which of the following conclusions could not be derived from Rutherford’s α -particle scattering experiment?

Which of the following options does not represent ground state electronic configuration of an atom?

The probability density plots of 1s and 2s orbitals are given in Fig. 2.1:

The density of dots in a region represents the probability density of finding electrons in the region.

On the basis of the above diagram which of the following statements is incorrect?

Which of the following statement is not correct about the characteristics of cathode rays?

Which of the following statements about the electron is incorrect?

Which of the following properties of atom could be explained correctly by Thomson Model of an atom?

Two atoms are said to be isobars if.

The number of radial nodes for 3p orbital is __________.

Number of angular nodes for 4d orbital is __________.

Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons?

Total number of orbitals associated with third shell will be __________.

Orbital angular momentum depends on __________.

Chlorine exists in two isotopic forms, Cl-37 and Cl-35 but its atomic mass is 35.5. This indicates the ratio of Cl-37 and Cl-35 is approximately

The pair of ions having same electronic configuration is __________.

For the electrons of oxygen atom, which of the following statements is correct?

If travelling at same speeds, which of the following matter waves have the shortest wavelength?

Identify the pairs which are not of isotopes?

Out of the following pairs of electrons, identify the pairs of electrons present in degenerate orbitals :

Which of the following sets of quantum numbers are correct?

In which of the following pairs, the ions are iso-electronic?

Which of the following statements concerning the quantum numbers are correct?

Arrange s, p and d sub-shells of a shell in the increasing order of effective nuclear charge (Z_eff) experienced by the electron present in them.

Show the distribution of electrons in oxygen atom (atomic number 8) using the orbital diagram.

Nickel atom can lose two electrons to form Ni²⁺ ion. The atomic number of nickel is 28. From which orbital will nickel lose two electrons.

Which of the following orbitals are degenerate?

3d_xy, 4d_xy, 3d_z² , 3d_yx, 4d_yx, 4d_zz

Calculate the total number of angular nodes and radial nodes present in 3p orbital.

The arrangement of orbitals on the basis of energy is based upon their (n+l ) value. Lower the value of (n+l ), lower is the energy. For orbitals having same values of (n+l), the orbital with a lower value of n will have lower energy.

I. Based upon the above information, arrange the following orbitals in the increasing order of energy

(a) 1s, 2s, 3s, 2p

(b) 4s, 3s, 3p, 4d

(c) 5p, 4d, 5d, 4f, 6s

(d) 5f, 6d, 7s, 7p

II. Based upon the above information, solve the questions given below :

(a) Which of the following orbitals has the lowest energy?

4d, 4f, 5s, 5p

(b) Which of the following orbitals has the highest energy?

5p, 5d, 5f, 6s, 6p

Which of the following will not show deflection from the path on passing through an electric field?

Proton, cathode rays, electron, neutron

An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom?

Wavelengths of different radiations are given below :

λ(A) = 300 nm

λ(B) = 300 μm

λ(c) = 3 nm

λ (D) 30 A°

Arrange these radiations in the increasing order of their energies.

The electronic configuration of the valence shell of Cu is 3d104s1 and not 3d94s2. How is this configuration explained?

The Balmer series in the hydrogen spectrum corresponds to the transition from n₁ = 2 to n₂ = 3,4,.......... This series lies in the visible region. Calculate the wavenumber of the line associated with the transition in Balmer series when the electron moves to n = 4 orbit. (R_H= 109677 cm^-1)

According to de Broglie, the matter should exhibit dual behaviour, that is both particle and wave-like properties. However, a cricket ball of mass 100 g does not move like a wave when it is thrown by a bowler at a speed of 100 km/h. Calculate the wavelength of the ball and explain why it does not show wave nature.

What is the experimental evidence in support of the idea that electronic energies in an atom are quantized?

Out of electron and proton which one will have, a higher velocity to produce matter waves of the same wavelength? Explain it.

A hypothetical electromagnetic wave is shown in Fig. 2.2. Find out the wavelength of the radiation.

Chlorophyll present in green leaves of plants absorbs light at 4.620 × 1014 Hz. Calculate the wavelength of radiation in nanometer. Which part of the electromagnetic spectrum does it belong to?

What is the difference between the terms orbit and orbital?

Table-tennis ball has a mass 10 g and a speed of 90 m/s. If speed can be measured within an accuracy of 4% what will be the uncertainty in speed and position?

The effect of the uncertainty principle is significant only for the motion of microscopic particles and is negligible for the macroscopic particles. Justify the statement with the help of a suitable example.

Hydrogen atom has only one electron, so mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?

Match the following species with their corresponding ground state electronic configuration.

Atom / Ion Electronic configuration

Match the quantum numbers with the information provided by these.

Quantum number Information provided

Match the following rules with their statements :

Match the following

Match the following

Match species are given in Column I with the electronic configuration given in Column II.

Column I Column II

Note: In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A): All isotopes of a given element show the same type of chemical behaviour.

Reason (R): The chemical properties of an atom are controlled by the number of electrons in the atom.

Note: In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A): Black body is an ideal body that emits and absorbs radiations of all frequencies.

Reason (R): The frequency of radiation emitted by a body goes from a lower frequency to higher frequency with an increase in temperature.

Note: In the following questions, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.

Assertion (A): It is impossible to determine the exact position and exact momentum of an electron simultaneously.

Reason (R): The path of an electron in an atom is clearly defined.

What is the photoelectric effect? State the result of a photoelectric experiment that could not be explained on the basis of laws of classical physics. Explain this effect on the basis of quantum theory of electromagnetic radiations.

Threshold frequency, ν₀ is the minimum frequency which a photon must possess to eject an electron from a metal. It is different for different metals. When a photon of frequency 1.0×1015 s^-1 was allowed to hit a metal surface, an electron having 1.988 × 10^-19 J of kinetic energy was emitted. Calculate the threshold frequency of this metal. Show that an electron will not be emitted if a photon with a wavelength equal to 600 nm hits the metal surface.

When an electric discharge is passed through hydrogen gas, the hydrogen molecules dissociate to produce excited hydrogen atoms. These excited atoms emit electromagnetic radiation of discrete frequencies which can be given by the general formula :

What points of Bohr’s model of an atom can be used to arrive at this formula? Based on these points derive the above formula giving description of each step and each term.

Calculate the energy and frequency of the radiation emitted when an electron jumps from n = 3 to n = 2 in a hydrogen atom.

Why was a change in the Bohr Model of the atom required? Due to which important development (s), concept of movement of an electron in an orbit was replaced by, the concept of probability of finding the electron in an orbital? What is the name given to the changed model of an atom?