Orbitals and Quantum Numbers
Orbitals are regions where electrons are likely to be found.
About this topic
An orbital is a region where an electron is likely to be found. s orbitals are spherical, p orbitals dumbbell-shaped, and d and f orbitals are more complex. Four quantum numbers describe each electron: n (energy level), l (subshell shape), ml (orbital orientation) and ms (spin, plus or minus one half).
The principal quantum number n is a positive whole number that sets the size and energy. The value of l runs from 0 to n minus 1, with 0 being s, 1 being p, 2 being d and 3 being f. The magnetic number ml ranges from minus l to plus l, so a p subshell has three orbitals and a d subshell has five. Each orbital holds two electrons with opposite spin, and no two electrons in an atom can have all four numbers identical.
For example, an electron in a 3p orbital has n = 3 and l = 1, and ml can be minus one, zero or plus one. The three p orbitals point along the x, y and z axes at right angles.
Orbitals explain bonding shapes and the structure of the periodic table. A misconception is that an orbital is a path; it is a probability map, often drawn to enclose about 90 percent of the chance of finding the electron. Heisenberg's uncertainty principle means we cannot know exact position and momentum together.
Key ideas
- s is spherical, p is dumbbell shaped
- n, l, m, s describe each electron
- Each orbital holds two electrons
Quick check
Use cases: where Orbitals and Quantum Numbers helps
- Homework: review the key idea behind Orbitals and Quantum Numbers before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Orbitals and Quantum Numbers without notes.
- Visual learning: play with the interactive lab to see how Orbitals and Quantum Numbers changes when you adjust its inputs.
- Teaching a friend: explain Orbitals and Quantum Numbers in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Orbitals and Quantum Numbers?
Orbitals are regions where electrons are likely to be found.
What will I learn in Orbitals and Quantum Numbers?
s is spherical, p is dumbbell shaped. n, l, m, s describe each electron. Each orbital holds two electrons.
Is Orbitals and Quantum Numbers part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Orbitals and Quantum Numbers lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Orbitals and Quantum Numbers?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.