Se - Selenium - periodic table of the elements

Seleinium has been widely researched as a critical element for warding off cancer. Taking 200-400mcg per day is said to decrease cancer risk by up to 70%. Selenium was discovered by J. J. Berzelius in 1817 in Sweden.

Atomic number	-	34		Density	g/mL	4	.8
Atomic weight	u	78	.96	Melting point	K	494
Bonding radius	A	1	.16	Boiling point	K	958
Atomic radius	A	1	.22	Heat of vaporization	kJ/mol	37	.7
Ionization Potential	V	9	.752	Heat of fusion	kJ/mol	6	.694
Electronegativity	-	2	.55	Specific heat	J/gK	0	.32
The oxide is a strong acid.				Crystal are hexagonal.
Electron configuration: [Ar] 3d¹⁰ 4s² 4p⁴

Other elements of the periodic table

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Ac ** Rf Db Sg Bh Hs Mt 110 111 112 113

Lanthanides* Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Actinides ** Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr