Which of the following statements is TRUE?
A) An orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy.
B) An orbital that penetrates into the region occupied by core electrons is more shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy.
C) It is possible for two electrons in the same atom to have identical values for all four quantum numbers.
D) Two electrons in the same orbital can have the same spin.
E) None of the above is true.

Question

Quizplus · Accepted Answer

An orbital that penetrates into the region occupied by core electrons experiences more nuclear charge than an orbital that does not penetrate. This means that the electron in the penetrating orbital is less shielded from the positive nuclear charge and experiences a higher effective nuclear charge, resulting in a lower energy level compared to the non-penetrating orbital. Therefore, statement A is true. Statement B is false because of this reason. Statement C is false because of the Pauli exclusion principle which states that no two electrons in an atom can have the same set of four quantum numbers. Statement D is false because of the Pauli exclusion principle and Hund's rule, which states that electrons in the same orbital must have opposite spins. Therefore, the correct answer is A.

Which of the Following Statements Is TRUE