Electron Configurations and Orbital Diagrams

Which statement best defines an electron configuration?

• The arrangement of protons in an atom’s nucleus

• The arrangement of electrons in an atom’s energy levels, sublevels, and orbitals

• The number of neutrons in each energy level

• The distribution of ions in a compound’s lattice

According to the Aufbau principle, electrons fill which energy levels first?

• Highest energy levels first to maximize stability

• Randomly among available orbitals

• Lowest energy levels first, then higher ones

• Only s sublevels before any p, d, or f

How many orbitals and maximum electrons does the s sublevel have?

• 1 orbital; maximum 2 electrons

• 3 orbitals; maximum 6 electrons

• 5 orbitals; maximum 10 electrons

• 7 orbitals; maximum 14 electrons

The Pauli Exclusion Principle states which requirement for electrons in the same orbital?

• They must have identical spins and energies

• They must spin in opposite directions and a maximum of two can occupy one orbital

• They must occupy different sublevels

• They must pair with protons in the nucleus

Which sublevel has five orbitals and can hold up to ten electrons?

• s sublevel

• p sublevel

• d sublevel

• f sublevel

Which sublevel has three orbitals and a maximum of six electrons?

• s

• p

• d

• f

Refer to the diagonal filling chart of sublevels and energy levels (s, p, d, f) with arrows indicating order. Which sequence correctly shows the order of electron filling at the start?

• 1s, 2p, 2s, 3p

• 1s, 2s, 2p, 3s

• 2s, 1s, 3p, 3s

• 1s, 3s, 2p, 2s

Using the filling order, what is the full electron configuration for oxygen (atomic number 8)?

• 1s2 2s2 2p4

• 1s2 2p6

• 1s2 2s2 3p4

• [He] 2p6

What is the electron configuration for hydrogen (atomic number 1)?

• 1s1

• 1s2

• 2s1

• 2p1

Which configuration is given for calcium (atomic number 20)?

• 1s2 2s2 2p6 3s2 3p6

• 1s2 2s2 2p6 3s2 3p6 4s2

• [Ar] 3d2

• [Ne] 3s2 3p6 4s2