Which of the following statements is TRUE?
A The principal quantum number (n) describes the shape of an orbital:
B The angular momentum quantum number (0 describes the the size and energy associated with an orbital.
C The magnetic quantum number (m) describes the orientation of the orbital.
D An orbital is the path that an electron follows during its movement in an atom:
E All of these are true:
The correct answer and explanation is:
The correct answer is: C. The magnetic quantum number (m) describes the orientation of the orbital.
Explanation:
Quantum numbers are used to describe the properties of atomic orbitals and the electrons within them. They include the principal quantum number (n), angular momentum quantum number (l), magnetic quantum number (m), and spin quantum number (ms).
A. The principal quantum number (n) describes the shape of an orbital is incorrect. The principal quantum number (n) determines the energy level and size of the orbital, not its shape. A larger value of n means the electron is farther from the nucleus and has more energy.
B. The angular momentum quantum number (l) describes the size and energy associated with an orbital is partially incorrect. The angular momentum quantum number (l) determines the shape of the orbital (not the size directly), such as spherical (s), dumbbell (p), etc. The energy of the orbital also depends on both n and l, especially in multi-electron atoms, but l alone does not describe size directly.
C. The magnetic quantum number (m) describes the orientation of the orbital is correct. The magnetic quantum number (m) specifies the orientation of the orbital in space relative to the other orbitals. For example, for p orbitals, m can have values of -1, 0, and +1, indicating the three possible orientations of a p orbital.
D. An orbital is the path that an electron follows during its movement in an atom is incorrect. Orbitals are not paths; they represent the probability distribution or “cloud” where an electron is likely to be found. Electrons do not follow fixed paths in orbitals, but rather exist in probabilistic regions defined by these orbitals.
E. All of these are true is incorrect because, as explained, not all the statements are accurate.
Thus, C is the only true statement.