Sodium atom in 3D
Salt and electrical signals. Sodium ions occur in common salt and help carry electrical signals in living systems. Explore the 3D model, inspect its parts and learn with guided explanations. Free on Atlas.
What you can learn
Salt and electrical signals. Sodium ions occur in common salt and help carry electrical signals in living systems.
Identify sodium from its proton count.
Count the neutrons in Sodium-23.
Inspect the occupied electron shells.
Compare the valence shell with a neighbouring element.
Explain what changes when an electron is lost.
Table salt contains sodium ions in a crystal lattice, not neutral sodium metal or separate NaCl molecules.
Try an investigation
Identify sodium from its proton count.
Check your understanding
What identifies an atom as sodium?
11 protons. Atomic number is proton count. Every sodium nucleus has 11 protons.
How many neutrons are in Sodium-23?
12. Neutrons = mass number − atomic number = 23 − 11 = 12. Mass number is not the average atomic weight of natural samples.
How many electrons are in a neutral sodium atom?
11. A neutral atom balances 11 positive protons with 11 negative electrons.
Which shell count describes neutral sodium in its ground state?
2, 8, 1. [Ne] 3s¹ gives 2, 8, 1 electrons across its occupied shells. Circular paths are only diagram guides.
If this atom loses one electron, what happens to its net charge?
It becomes +1. Losing one negative electron leaves one more proton than electrons. Its 11 protons still identify it as sodium.
What can this 3D shell model tell you reliably?
The particle counts for the selected neutral isotope. The counts represent a defined isotope and neutral atom. Particle sizes, spacing and circles are simplified teaching symbols.
Sources and model scope
An educational representation. The explorer identifies its data sources, scale choices and simplifications.