Cobalt 27

Atomic No. Order:

Alphabetic Order:

Periodic Table

2, 8,

15, 2

Co
27

Rh
45

Ir
77

Mt
109

Upe
159

Bne
209

Cobalt

Symbol

Atomic Number

Relative Atomic Mass
¹²C = 12.0000

58.933 200 (±9) [Since 1995]

Atomic Radius pm

125

First Ionisation Energy
kJ mol ^-1

760.0

Ionisation Energy (eV)

7.8810

Electronegativity

1.88

Density kg m ^-3

8900 [293 K]
7970 [m.p.]

Molar Volume cm ³

6.62

Thermal Conductivity
W m ^-1 K ^-1

100 [300 K]

Melting Point K

1768

Boiling Point K

3143

Number of Isotopes

Isotope Atomic mass/u Mole fraction

59Co 58.933 1999(15) 1.0000

Inner + outer Shells

Inner + outer Orbitals

Filling Orbital

3d ⁷

Ground State Electron
Configuration

[Ar]

3d ⁷

4s ²

Ground State Electron
Configuration with
free Orbitals (n= 9)

0, 0, 3, 6

Ground State Electron
Configuration with
compressed Orbitals (n= 24)

0, 0, 0, 24

Singularity

	s	p	d		f	g	h	i	j
1	2
2	2	6
3	2	6	7	3
4	2	6	10		14
5
6
7

Term Symbol

⁴F _9/2

Discovery

It was discovered in 1735 by the Swedish chemist Georg Brandt (Stockholm, Sweden).

Name Derived From

The name derives from the German Kobald for "evil spirits or goblins", who were superstitiously thought to cause trouble for miners because the mineral contained arsenic that injured their health and the metallic ores did not yield metals when treated with the normal methods.

APSIDIUM ©	Created:	2002-06-01	027.pdf
	Page update:	2004-12-08	027.pdf