First 20 elements of the periodic table: This article provides a comprehensive list of the first 20 elements in the periodic table along with their atomic numbers and symbols.

There are actually a few things that help explain the dissonance between elements’ names and their symbols, says Sam Kean, author of The Disappearing Spoon and occasional Mental_Floss contributor.

The element symbol always starts with a capital letter. Any letters that follow will be lower case letters, for example, helium is He. Some element symbols are simple.

The International Union of Pure and Applied Chemistry has approved the name and symbols for four elements: nihonium (Nh), moscovium (Mc), tennessine (Ts), and oganesson (Og), respectively for ...