Selenium or se

• atomic number is 34

• atomic weight is 78.96

• color is Gray

• state at 298.15°k is Solid

• classification is Nonmetelic

• date of discovery is 1817

• density kg/m^3 is 4790

• melting point is 494.15

• boiling point is 1746 K

• group is Nonmetal

• Number of neutron is 45