Question

Which of the following statements about quantum theory is incorrect?

		a.	The energy and position of an electron cannot be determined simultaneously.
		b.	Lower energy orbitals are filled with electrons before higher energy orbitals.
		c.	When filling orbitals of equal energy, two electrons will occupy the same orbital before filling a new orbital.
		d.	No two electrons can have the same four quantum numbers.
		e.	All of these are correct.

The answer is C for Hund's rule but why A is correct?

I think that the uncertainty principle is about [ position-momentum ] and [ time-energy ] .

Answer 1

Answer.

The incorrect statement about Quantum theory is the option ( c )

" when filling orbitals of equal energy, two electrons will occupy the same orbital before filling a new orbital.'

.

Explanation: This is because, the statement is against the Hund's rule of maximum multiplicity. As per that rule, when filling orbitals of equal energy, electron pairing doesnot take place until all available orbitals filled with one electron each.

Let us check the other options.

a. The energy and position of an electron cannot be determined simultaneously.

This is as per the Heisenberg's uncertainty principle and the statement is correct.

b. Lower energy orbitals are filled with electrons before higher energy orbitals.

This is as per aufbau principle and the statement is correct.

c. When filling orbitals of equal energy, two electrons will occupy the same orbital before filling a new orbital.

It is the incorrect statement and explained above.

d. No two electrons can have the same four quantum numbers.

This is as per the Pauli exclusion principle and the statement is correct.