Here you can read more about the chemical element Selenium. Its shemical symbol is Se and its atomic number is 34. The relative atomic mass of Selenium is 78.96 u. The elemental classification of Selenium is Polyatomic nonmetals, and it belongs to group 16 and period 4 in the Periodic Table of Elements.
The density of Selenium is 4790 kg/m3. And the mineral hardness of Selenium is 2 Mohs. The melting point of Selenium is 490 Kelvin (217 ℃). The boiling point of Selenium is 958 Kelvin (685 ℃). Selenium was discovered in the year 1817 by Jöns Jakob Berzelius and Johann Gottlieb Gahn.
To the right (or below if you are using a mobile device with a smaller screen) you will find the information given above for the element Selenium ordered in tabular form, which might be easier to read and use if you want to quantify it in some sort.