Electron Configuration How to write electron configurations orbital

Electron Configuration How to write electron configurations, orbital notations, and Noble Gas configurations

Properties of Electrons • Electrons don’t behave like normal particles. They also act like waves. Because they act like waves, their exact location around the nucleus cannot be calculated. • Bohr’s examination of the hydrogen atom also found that electrons were only allowed to have specific amounts of energy. Other energies are forbidden. The allowed energy of an electron around an atom is called a quantum. • Because we can’t see electrons in specific orbits, electrons are contained in orbitals around atoms. Orbitals are calculated regions of space where electrons can exist. Each orbital can

Orbitals • Orbitals have four sublevels: s, p, d, and f. Orbital sublevel What energy levels can they exist at? How many types of these orbitals can exist at any energy level? What is the maximum number of electrons that can be held by these orbitals at any energy level? s 1 st and higher 1 2 3 6 5 10 7 14 p d f 2 nd and higher 3 rd and higher 4 th and higher

Rules for filling orbitals There are three rules for filling orbitals. • Aufbau Principle: Electrons always fill the lowest energy levels first. – Electrons start at the bottom and work their way up. – This also implies that electrons fill orbitals the same way every time. • Pauli Exclusion Principle: No two electrons with the same energy characteristics can occupy an orbital at the same time. – One electron must be spin up and the other electron must be spin down. • Hund’s Rule: When filling multiple orbitals of the same sublevel (p, d, and f), electrons half-fill the sublevel first before pairing electrons.

Orbital Energy

Order for Filling Orbitals • • 7 s 6 s 5 s 4 s 3 s 2 s 1 s 7 p 6 p 5 p 4 p 3 p 2 p 7 d 6 d 5 d 4 d 3 d 7 f 6 f 5 f 4 f

Connections to the Periodic Table • The first two columns of the periodic table are the s-block. • The last six columns of the periodic table are the p-block. • The middle ten columns of the periodic table are the d-block. Remember that d-block elements fill one energy level late! After 3 p is filled, 4 s is filled, then 3 d is filled, and then 4 p is filled. • The bottom two rows of the periodic table are the f-block. Remember that f-block elements fill two energy levels late! After 5 p is filled, 6 s is filled, then 4 f is filled, then 5 d is filled, then 6 p is filled.

Color-code and label your periodic table!