This list includes 7 Chemical Elements that start with A, from “Actinium” to “Astatine”. They include metals, metalloids, and a rare halogen, and they appear in medicine, industry, and research. See the A–Z index for other letters.

Chemical Elements that start with A are the elements whose English names begin with the letter A. Actinium is historically important in radiotherapy research, while astatine is notable for its extreme rarity and instability.

Below you’ll find the table with atomic number, element name, atomic weight, and discovery year.

Atomic number: The whole-number position of the element in the periodic table; you use it to identify and sort elements quickly.

Element name: The element’s English name, which helps you recognize common uses, historical notes, and literature references.

Atomic weight: The standard atomic weight given to three decimals; you can use it to compare relative mass and estimate quantities.

Discovery year: The year or period when the element was first isolated or reported; you use it to follow historical discovery timelines.

Chemical Elements that start with A

Descriptions