Question 3: a) Supply the missing quantum number(s) and subshell name(s): i. n = 4, l = 1, ml = 0, Subshell = ? ii. n = 3, l = 2, ml = -2, Subshell = ? iii. n = ?, l = 0, ml = 0, Subshell = 2s b) Consider the element with the ground-state electron configuration 1s²2s²2p⁴. Identify this element (by name, not symbol). c) Write the complete ground-state electron configuration for a Sc atom.

Question 3: a) Supply the missing quantum number(s) and subshell name(s): i. n = 4, l = 1, ml = 0, Subshell = ? ii. n = 3, l = 2, ml = -2, Subshell = ? iii. n = ?, l = 0, ml = 0, Subshell = 2s b) Consider the element with the ground-state electron configuration 1s²2s²2p⁴. Identify this element (by name, not symbol). c) Write the complete ground-state electron configuration for a Sc atom.

Answer

a) Missing quantum numbers and subshell names: i. For n = 4 and l = 1, the subshell is 4p (where l = 1 corresponds to 'p'). ii. For n = 3 and l = 2, the subshell is 3d (where l = 2 corresponds to 'd'). iii. For the 2s subshell, the principal quantum number n is 2. b) Ground-state electron configuration 1s²2s²2p⁴: Summing the electrons: 2 + 2 + 4 = 8. The element with atomic number 8 is Oxygen. c) Ground-state electron configuration for a Scandium (Sc) atom: Scandium has an atomic number of 21. Following the Aufbau principle, the electrons fill orbitals in order of increasing energy: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹.