Selenium

34
Se
Kumpulan
16
Kala
4
Blok
p
Proton
Elektron
Neutron
34
34
45
Ciri-Ciri Am
Nombor atom
34
Berat atom
78.96
Nombor jisim
79
Kategori
Bukan logam
Warna
Kelabu
Radioaktif
Tidak
From the Greek word Selene, moon
Struktur hablur
Monoklinik Ringkas
Sejarah
Selenium was first observed in about the year 1300 by the alchemist Arnold of Villanova.

Selenium was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn who noted the similarity of the new element to the previously-known tellurium.

In 1873, Willoughby Smith found that the electrical resistance of grey selenium was dependent on the ambient light.
Bilangan elektron per petala
2, 8, 18, 6
Konfigurasi elektron
[Ar] 3d10 4s2 4p4
Se
Selenium deficiency in animals can lead to slow growth
Ciri-Ciri Fizikal
Fasa
Pepejal
Ketumpatan
4.809 g/cm3
Takat lebur
494.15 K | 221 °C | 429.8 °F
Takat didih
958.15 K | 685 °C | 1265 °F
Haba pelakuran
5.4 kJ/mol
Haba pengewapan
26 kJ/mol
Muatan haba molar
0.321 J/g·K
Banyak pada kerak bumi
5×10-6%
Banyak pada alam semesta
3×10-6%
Ultrapure
Kredit imej: Images-of-elements
Ultrapure black, amorphous selenium
Nombor CAS
7782-49-2
PubChem CID Number
6326970
Ciri-Ciri Atom
Jejari atom
120 pm
Jejari kovalen
120 pm
Keelektronegatifan
2.55 (Skala Pauling)
Kebolehan mengion
9.7524 eV
Isipadu atom
16.45 cm3/mol
Daya pengaliran terma
0.0204 W/cm·K
Keadaan pengoksidaan
-2, 2, 4, 6
Aplikasi
Selenium is used in the glass industry to decolorize glass and to make red-colored glasses and enamels.

It is used as a catalyst in many chemical reactions.

It is also used as a photographic toner, and as an additive to stainless steel.

Selenium sulfide is used in anti-dandruff shampoos.
Many of selenium's compounds, such as selenates and selenites, are highly toxic
Isotop
Isotop stabil
74Se, 76Se, 77Se, 78Se, 80Se
Isotop tidak stabil
65Se, 66Se, 67Se, 68Se, 69Se, 70Se, 71Se, 72Se, 73Se, 75Se, 79Se, 81Se, 82Se, 83Se, 84Se, 85Se, 86Se, 87Se, 88Se, 89Se, 90Se, 91Se, 92Se, 93Se, 94Se