Selenium (Se)

About Selenium

Selenium is a chemical element with the symbol Se and atomic number 34, meaning every atom has 34 protons in its nucleus. It is classed as Nonmetal and is a solid at room temperature. Its atomic mass is about 78.971 atomic mass units (u).

On the periodic table, Selenium sits in group 16, period 4, which determines how many electron shells it has and how it tends to react with other elements.

Uses of Selenium

In daily life and industry, Selenium is used for Solar cells, supplements. These uses are closely tied to the typical properties of elements in the Nonmetal category.

Electron Structure of Selenium

Using a simplified electron shell model (at most 2 electrons in the first shell, 8 in the second, 18 in the third, and so on), Selenium has 4 electron shells, with an approximate arrangement of 2, 8, 18, 6 electrons from the innermost shell to the outermost. This is a simplified learning model, not the full electron configuration that accounts for the s, p, d and f subshells.

Explore Other Elements

Want to see another element or try the element symbol quiz? Go back to the Interactive Periodic Table to explore all 118 chemical elements.

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