Question

24. Which of the following statements are correct? i) Hund's Rule states orbitals must be filled with electrons in order of lowest to highest energy. 11) The Aufbau Principle states that if electrons occupy degenerate orbitals, they must be half filled first. ill) The Heisenberg Uncertainty Principle states that the position and velocity of an electron cannot be determined simultaneously. iv) The ultraviolet catastrophe was that as the temperature of a blackbody increased, it would emit an infinite amount of light with very long wavelengths. v) To increase the "brightness" of monochromatic light, the amplitude of the wave is increased and the wavelength remains the same. (a) ili and v are correct. b) and ii are correct. c) None are correct. d) ii and iv are correct. e) ili andvere correct.

Answer 1

Hund's rule states that:

1. Every orbital in a sublevel is singly occupied before any orbital is doubly occupied.
2. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).

The Aufbau Principle states that in the ground state of an atom, an electron enters the orbital with the lowest energy first and subsequent electrons are fed in the order of increasing energies

The Heisenberg uncertainty principle states that it is impossible to know simultaneously the exact position and momentum of a particle. That is, the more exactly the position is determined, the less known the momentum, and vice versa.

The ultraviolet catastrophe states that an ideal black body (also blackbody) at thermal equilibrium will emit radiation in all frequency ranges, emitting more energy as the frequency increases.

Brightness depends on light wave amplitude, the height of light waves.and colour depends on the wavelength .

So the correct options is (a) iii and v are correct