Selenium Element in Periodic Table | Atomic Number Atomic Mass

Selenium Element:

Selenium is the chemical in the 16^th group and 4^th period of the periodic table. It is indicated by the symbol Se and the atomic number of selenium is 34. Se is a non-metal. Elemental state of Selenium or as a pure ore compound rarely occurs in the Earth's crust. It contains seven natural isotopes, including ⁷⁴Se, ⁷⁶Se, ⁷⁷Se, ⁷⁸Se, ⁷⁹Se, ⁸⁰Se, ⁸²Se as well as 23 other synthetic isotopes.

Uses Of Selenium Element:

• Today the biggest use of selenium is glassmaking.
• Se is also used to make pigments for ceramics, paint and plastics.
• Selenium is a semiconductor and is used in photocells, solar cells and photocopiers.
• It is used in some anti-dandruff shampoos because it is toxic to the scalp fungus that causes dandruff.
• Se  is also used as an additive to make stainless steel.
• Selenium is an essential trace element for some species, including humans. Small amount of selenium can cause health problems; but large amount is much dangerous since it is carcinogenic in nature and teratogenic deforming foetal development in humans.

Selenium Element Information:

Discovery year: 1817

Discovered by: Jöns Jakob Berzelius and Johann Gottlieb Gahn

Atomic number: 34

Relative atomic mass: 78.971 

Electron configuration: [Ar] 3d¹⁰ 4s² 4p⁴

Block: p-block

Other elements in the same block:

Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Aluminium, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Gallium, Germanium, Arsenic, Bromine, Krypton, Indium, Tin, Antimony, Tellurium, Iodine, Xenon, Thallium, Lead, Bismuth, Polonium, Astatine, Radon, Nihonium, Flerovium, Moscovium, Livermorium, Tennessine and Oganesson are the same block elements.

Period: period 4

Other elements in the same period:

Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Germanium, Arsenic, Bromine and Krypton.

Group: group 16 (chalcogens)

Other elements in the same group:

Oxygen, Sulfur, Tellurium, Polonium and Livermorium are the same group elements.

Other elements in the same orbital:

Gallium, Germanium, Arsenic, Bromine and Krypton are the elements in the same orbital.

Allotropes: none

Key isotopes: ⁸⁰Se 

Melting point: 220.8°C, 429.4°F, 494 K 

Boiling point: 685°C, 1265°F, 958 K 

Element category:  polyatomic non-metal

Density (g cm⁻³): 4.809 

CAS number: 7782-49-2

Color: black, red, and gray allotropes

You can know detailed information for each element,

Hydrogen, Helium, LithiumBeryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine,  Neon , Sodium, Magnesium, Aluminium, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Germanium, Arsenic, Selenium, Bromine, Krypton,  Rubidium, Strontium, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium, Indium, Tin, Antimony, Tellurium, Iodine, Xenon,  Caesium, Barium, Lanthanum,  Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Tantalum, Tungsten, Rhenium, Osmium, Iridium, Platinum, Gold, Mercury, Thallium, Lead, Bismuth, Polonium, Astatine, Radon,  Francium, Radium, Actinium, Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Curium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium, Nobelium, Lawrencium, Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Copernicium, Nihonium, Flerovium, Moscovium, Livermorium, Tennessine, Oganesson.