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प्रश्न
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.
विकल्प
Both A and R are true and R is the correct explanation of A.
Both A and R are true and R is not the correct explanation of A.
A is true and R is false.
Both A and R are false.
उत्तर
A is true and R is false.
Explanation:
To Heisenberg's uncertainty principle it is impossible to determine simultaneously the exact position and exact momentum (or velocity) of an electron. Thus it implies that determining the trajectory of an electron is impossible as it requires exact position and velocity which is not possible as per the uncertainty principle.
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संबंधित प्रश्न
If the position of the electron is measured within an accuracy of ± 0.002 nm, calculate the uncertainty in the momentum of the electron. Suppose the momentum of the electron is h/4πm × 0.05 nm, is there any problem in defining this value.
Which of the following does not represent the mathematical expression for the Heisenberg uncertainty principle?
The quantum mechanical treatment of the hydrogen atom gives the energy value:
En = `(-13.6)/"n"^2` ev atom−1
- use this expression to find ΔE between n = 3 and n = 4
- Calculate the wavelength corresponding to the above transition.
The Li2+ ion is a hydrogen like ion that can be described by the Bohr model. Calculate the Bohr radius of the third orbit and calculate the energy of an electron in 4th orbit.
Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons?
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 uncertainty principle is significant only for motion of microscopic particles and is negligible for the macroscopic particles. Justify the statement with the help of a suitable example.
Match the following rules with their statements :
| Rules | Statements |
| (i) Hund's Rule | (a) No two electrons in an atom can have the same set of four quantum numbers. |
| (ii) Aufbau Principle | (b) Half-filled and completely filled orbitals have extra stability. |
| (iii) Pauli Exclusion Principle | (c) Pairing of electrons in the orbitals belonging to the same subshell does not take place until each orbital is singly occupied. |
| (d) It is impossible to determine the exact position and exact momentum of a subatomic particle simultaneously. |
|
| (iv) Heisenberg's Uncertainty Principle |
(e) In the ground state of atoms, orbitals are filled in the order of their increasing energies. |
Uncertainty principle was given by ______.
In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainty with which the position of the electron can be located is ______.
(h = 6.6 × 10−34 kg m2s−1, mass of electron, em = 9.1 × 10−31 kg)
