Unit 1: Atoms, compounds, and ions Introduction to the atom History of atomic structure Quantum numbers and orbitals Electron configurations Introduction to the periodic table Periodic table …

In this article, we’ll look in more detail at the periodic table, how atoms organize their electrons, and how this allows us to predict the reactivity of elements.

The periodic table organizes elements into groups and periods based on their chemical and physical properties. Elements in the same group share similar characteristics, like reactivity. …

And to help us with that, we will look at a periodic table of elements. And so first, let's just think about the electron configuration of the simplest element.

Now let's go to the other end of the periodic table and say, look at chlorine. Chlorine is a halogen. Halogens have seven valence electrons so chlorine's valence electrons would look like this. It …

The easiest way to create electron configurations is using an electron configuration table, which is a way of writing down the various orbitals available to electrons.

Atomic structure Learn about the three subatomic particles that make up atoms: protons, neutrons, and electrons. Understand how these particles are represented on the periodic table.

Learn how to determine the number of valence electrons for an element using the periodic table.

Check your understanding of the structure of the periodic table in this set of free, standards-aligned practice questions.

Is there a trick to remember the valence electrons of various elements without taking help of the periodic table?