Discovering the Elements
A timeline of when elements were first discovered
Elements are arranged from top to bottom in order of their atomic number with the lowest at the top. One continuous line is drawn through each element in the order it was first used, observed, or predicted—creating a colorful timeline. The larger the distance between two elements atomic numbers, the larger the curve. The color ranges from dark for the oldest elements like copper (9000 BCE) and lead (7000 BCE) to light for the newest like tennessine and moscovium (2010). Each element is labeled with its atomic number, name, and when it was discovered along the timeline.