IMAT Chemistry Practice Exam

In sp hybridization, one s orbital mixes with one p orbital to form two equivalent hybrid orbitals. The hybrid orbitals are described as a linear combination with equal weight of s and p, so the coefficients are the same (1/√2 for each). When you square those coefficients to get percentages, you get 50% s character and 50% p character for each sp hybrid orbital. That’s why the s and p character percent values are equal. For context, sp2 hybrids have about 33% s and 67% p, and sp3 hybrids have about 25% s and 75% p, reflecting how many p orbitals participate in the mixing.