Abstract: In the process of teaching college physics, detailed analysis of some elementary concepts is impor- tant both for deeper understanding of the concepts itself and holding the idea of the modern physics, as well as pro- ceeding to later curriculums. By studying the angular momentum and its properties under the parity transformation, the concept of axial vector is introduced. The parity transformation in quantum mechanics is analyzed such that the state wave function and the field operator are classified. The important concept such as the parity is strengthened due to its importance in classifying the composite particles in elementary particle physics.

Key words: angular momentum, parity, quantum number, composite particle