4.3 🧠electron configuration

What does the aufbau principle state?

• A maximum of two electrons can occupy a single atomic orbital

• Each electron occupies the highest energy orbital available.

• Each electron occupies the lowest energy orbital available.

• Single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals.

Which of the following is the electron configuration of helium?

• 1s1

• 1s2

• 1p1

• 1s22s22p6

Which of the following is true?

• Valence electrons do not determine chemical properties.

• Valence electrons are in an atom’s innermost orbital.

• Valence electrons are generally associated with the atom’s highest principal energy level.

• Valence electrons are not involved in forming chemical bonds.

The electron configuration of ground state carbon is 1s22s22p2. How many electrons are in the third p orbital?

• 1

• 2

• 4

• 0