Quantum Numbers

Front

What are quantum numbers?

Back

Quantum numbers are values that describe the energy levels, orbitals, and spin of electrons in an atom.

Front

What is the principal quantum number (n)?

Back

The principal quantum number (n) indicates the main energy level of an electron in an atom and can take positive integer values (1, 2, 3, ...).

Front

What does the angular momentum quantum number (l) represent?

Back

The angular momentum quantum number (l) represents the shape of the orbital and can take integer values from 0 to (n-1).

Front

What is the magnetic quantum number (m_l)?

Back

The magnetic quantum number (m_l) indicates the orientation of the orbital in space and can take values from -l to +l.

Front

What is the spin quantum number (m_s)?

Back

The spin quantum number (m_s) describes the intrinsic spin of an electron and can be either +1/2 or -1/2.

Front

What is the value of m_s for an electron with spin up?

Back

+1/2

Front

What is the value of m_s for an electron with spin down?

Back

-1/2

Front

For lithium (Li), what is the value of the principal quantum number (n)?

Back

1 for the first electron, 2 for the second electron.

Front

For iron (Fe), what is the value of the angular momentum quantum number (l) for the outermost electron?

Back

2 (d orbital).

Front

What is the maximum number of electrons that can occupy a single orbital?

Back

2 electrons, due to the Pauli exclusion principle.