Electronic Structure - GCSE Chemistry Definition

The electronic structure of an atom describes how the electrons are arranged around its nucleus. Electrons travel in areas called energy levels or shells, which are like layers around the centre of the atom. The first energy level can hold up to 2 electrons, while the second and third can each hold up to 8. For example, the electronic structure of a Sodium atom, Na, which has a total of 11 electrons is 2.8.1. This means Na has 2 electrons in the first shell, 8 in the second shell and then 1 in the third shell. You can think of it like seats in a bus, where each level fills up before starting another one. The electronic structure is important because it helps us understand how atoms join together to form compounds and why they react in certain ways in chemical reactions.