Selenium Element (Periodic Table)

Selenium (Se) is a chemical element of the periodic table, located in the group 16 and the period 4, and has the atomic number 34. It is a red powder or black reactive nonmetal, whose name comes from the Greek word “selene”, which means Moon. It is a member of the chalcogen group.

group

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5

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7

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9

10

11

12

13

14

15

16

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period

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1

1 H Click on the image to learn more! Hydrogen

2 He Click on the image to learn more! Helium

2

3 Li Click on the image to learn more! Lithium

4 Be Click on the image to learn more! Beryllium

5 B Click on the image to learn more! Boron

6 C Click on the image to learn more! Carbon

7 N Click on the image to learn more! Nitrogen

8 O Click on the image to learn more! Oxygen

9 F Click on the image to learn more! Fluorine

10 Ne Click on the image to learn more! Neon

3

11 Na Click on the image to learn more! Sodium

12 Mg Click on the image to learn more! Magnesium

13 Al Click on the image to learn more! Aluminium

14 Si Click on the image to learn more! Silicon

15 P Click on the image to learn more! Phosphorus

16 S Click on the image to learn more! Sulfur

17 Cl Click on the image to learn more! Chlorine

18 Ar Click on the image to learn more! Argon

4

19 K Click on the image to learn more! Potassium

20 Ca Click on the image to learn more! Calcium

21 Sc Click on the image to learn more! Scandium

22 Ti Click on the image to learn more! Titanium

23 V Click on the image to learn more! Vanadium

24 Cr Click on the image to learn more! Chromium

25 Mn Click on the image to learn more! Manganese

26 Fe Click on the image to learn more! Iron

27 Co Click on the image to learn more! Cobalt

28 Ni Click on the image to learn more! Nickel

29 Cu Click on the image to learn more! Copper

30 Zn Click on the image to learn more! Zinc

31 Ga Click on the image to learn more! Gallium

32 Ge Click on the image to learn more! Germanium

33 As Click on the image to learn more! Arsenic

34 Se Click on the image to learn more! Selenium

35 Br Click on the image to learn more! Bromine

36 Kr Click on the image to learn more! Krypton

5

37 Rb Click on the image to learn more! Rubidium

38 Sr Click on the image to learn more! Strontium

39 Y Click on the image to learn more! Yttrium

40 Zr Click on the image to learn more! Zirconium

41 Nb Click on the image to learn more! Niobium

42 Mo Click on the image to learn more! Molybdenum

43 Tc Click on the image to learn more! Technetium

44 Ru Click on the image to learn more! Ruthenium

45 Rh Click on the image to learn more! Rhodium

46 Pd Click on the image to learn more! Palladium

47 Ag Click on the image to learn more! Silver

48 Cd Click on the image to learn more! Cadmium

49 In Click on the image to learn more! Indium

50 Sn Click on the image to learn more! Tin

51 Sb Click on the image to learn more! Antimony

52 Te Click on the image to learn more! Tellurium

53 I Click on the image to learn more! Iodine

54 Xe Click on the image to learn more! Xenon

6

55 Cs Click on the image to learn more! Caesium

56 Ba Click on the image to learn more! Barium

72 Hf Click on the image to learn more! Hafnium

73 Ta Click on the image to learn more! Tantalum

74 W Click on the image to learn more! Tungsten

75 Re Click on the image to learn more! Rhenium

76 Os Click on the image to learn more! Osmium

77 Ir Click on the image to learn more! Iridium

78 Pt Click on the image to learn more! Platinum

79 Au Click on the image to learn more! Gold

80 Hg Click on the image to learn more! Mercury

81 Tl Click on the image to learn more! Thallium

82 Pb Click on the image to learn more! Lead

83 Bi Click on the image to learn more! Bismuth

84 Po Click on the image to learn more! Polonium

85 At Click on the image to learn more! Astatine

86 Rn Click on the image to learn more! Radon

7

87 Fr Click on the image to learn more! Francium

88 Ra Click on the image to learn more! Radium

104 Rf Click on the image to learn more! Rutherfordium

105 Db Click on the image to learn more! Dubnium

106 Sg Click on the image to learn more! Seaborgium

107 Bh Click on the image to learn more! Bohrium

108 Hs Click on the image to learn more! Hassium

109 Mt Click on the image to learn more! Meitnerium

110 Ds Click on the image to learn more! Darmstadtium

111 Rg Click on the image to learn more! Roentgenium

112 Cn Click on the image to learn more! Copernicium

113 Nh Click on the image to learn more! Nihonium

114 Fl Click on the image to learn more! Flerovium

115 Mc Click on the image to learn more! Moscovium

116 Lv Click on the image to learn more! Livermorium

117 Ts Click on the image to learn more! Tennessine

118 Og Click on the image to learn more! Oganesson

57 La Click on the image to learn more! Lanthanum

58 Ce Click on the image to learn more! Cerium

59 Pr Click on the image to learn more! Praseodymium

60 Nd Click on the image to learn more! Neodymium

61 Pm Click on the image to learn more! Promethium

62 Sm Click on the image to learn more! Samarium

63 Eu Click on the image to learn more! Europium

64 Gd Click on the image to learn more! Gadolinium

65 Tb Click on the image to learn more! Terbium

66 Dy Click on the image to learn more! Dysprosium

67 Ho Click on the image to learn more! Holmium

68 Er Click on the image to learn more! Erbium

69 Tm Click on the image to learn more! Thulium

70 Yb Click on the image to learn more! Ytterbium

71 Lu Click on the image to learn more! Lutetium

89 Ac Click on the image to learn more! Actinium

90 Th Click on the image to learn more! Thorium

91 Pa Click on the image to learn more! Protactinium

92 U Click on the image to learn more! Uranium

93 Np Click on the image to learn more! Neptunium

94 Pu Click on the image to learn more! Plutonium

95 Am Click on the image to learn more! Americium

96 Cm Click on the image to learn more! Curium

97 Bk Click on the image to learn more! Berkelium

98 Cf Click on the image to learn more! Californium

99 Es Click on the image to learn more! Einsteinium

100 Fm Click on the image to learn more! Fermium

101 Md Click on the image to learn more! Mendelevium

102 No Click on the image to learn more! Nobelium

103 Lr Click on the image to learn more! Lawrencium

– p block

Selenium Element Information

Selenium is found in the fourth row of the periodic table below the sulfur element.
Origin of name	Greek word “selene” (which means Moon)
Symbol	Se
Atomic number (Z)	34
Atomic mass	78.96 u
Block	p-block
Group	16 (oxygen group)
Period	4
Classification	Reactive nonmetal
Atomic radius	120 pm
Covalent radius	120±4 pm
Van der Waals radius	190 pm
Melting point	221 ℃, 430 ℉, 494 K
Boiling point	685 ℃, 1265 ℉, 958 K
Electron configuration	[Ar] 3d10 4s2 4p4
Learn how to write: Selenium Electron Configuration
Electrons per shell	2, 8, 18, 6
Learn how to draw: Selenium Bohr Model
Crystal structure	Trigonal
Phase at r.t	Solid
Density near r.t	Gray: 4.81 g/cm3 Alpha: 4.39 g/cm3 Vitreous: 4.28 g/cm3
Main isotopes	Selenium-74, Selenium-76, Selenium-77, Selenium-78, Selenium-80
Natural occurrence	Primordial
Oxidation state	-2, +2, +4, +6
Electronegativity (Pauling scale)	2.55
Protons Neutrons Electrons	34 45 34
Learn how to find: Selenium Protons Neutrons Electrons
Valence electrons	6
Learn how to find: Selenium Valence Electrons
CAS number	7782-49-2
Discovered by	Jons Jakob Berzelius and Johann Gottlieb Gahn in 1817

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Related:

• Periodic Table

More Elements:

External Links:

• https://www.rsc.org/periodic-table/element/34/selenium
• https://en.wikipedia.org/wiki/Selenium
• https://www.britannica.com/science/selenium
• https://education.jlab.org/itselemental/ele034.html
• https://www.chemicool.com/elements/selenium.html
• https://pubchem.ncbi.nlm.nih.gov/element/Selenium
• https://www.radiochemistry.org/periodictable/elements/34.html