Question

Which of the following are not allowed? State which rule is violated for any that are not allowed. (a) 1p^3 (b) 2p^8 (c) 3g^{11} (d) 4f^2

a) (a) Not allowed; violates the Pauli exclusion principle.

b) (b) Allowed.

c) (c) Not allowed; violates the orbital lettering convention.

d) (d) Not allowed; violates the allowed range for l in a given shell.

Answer 1

The spectroscopic notations (a) 1p³, and (b) 2p¸ are not allowed due to violations of the n+p rule and Pauli's exclusion principle respectively. The notation (c) 3g¹¹ also violates the orbital lettering convention, while (d) 4f² is the only allowed configuration listed.

Step-by-step explanation:

The student's question pertains to the electron configurations and the rules that govern them, which are derived from principles in quantum mechanics. Here are the answers:

• (a) 1p³ - Not allowed; violates the n+p rule. For n=1, only s orbitals are available, thus p orbitals start from n=2.
• (b) 2p¸ - Not allowed; violates Pauli's exclusion principle and Hund's rule. A p subshell can hold a maximum of 6 electrons.
• (c) 3g¹¹ - Not allowed; violates the orbital lettering convention. The letters s, p, d, and f correspond to l=0,1,2,3 respectively, g orbitals would correspond to l=4 and they do not exist in n=3 shell.
• (d) 4f² - Allowed. The 4f subshell can hold up to 14 electrons, and in this case, it has only 2, which does not violate any rule.