Neodymium 60

Atomic No. Order:

Alphabetic Order:

Periodic Table

2, 8, 18,

22, 8, 2

Nd
60

U
92

Uqb
142

Ueb
192

Neodymium

Symbol

Atomic Number

Relative Atomic Mass
¹²C = 12.0000

144.24(3)

Atomic Radius pm

182

First Ionisation Energy
kJ mol ^-1

529.6

Electronegativity

1.14

Density kg m ^-3

7007 [293 K]

Molar Volume cm ³

20.59

Thermal Conductivity
W m ^-1 K ^-1

16.5 [300 K]

Melting Point 1294 K

1,870 F / 1,021 C

Boiling Point 3341 K

5,554 F / 3,068 C

Specific gravity

7.007 (25 C)

Number of Isotopes

Isotope Atomic mass/u Mole fraction

142Nd 141.907 719(3) 0.272(5)
143Nd 142.909 810(3) 0.122(2)
144Nd 143.910 083(3) 0.238(3)
145Nd 144.912 569(3) 0.083(1)
146Nd 145.913 113(3) 0.172(3)
148Nd 147.916 889(4) 0.057(1)
150Nd 149.920 887(4) 0.056(2)

Inner/outer Shells

Inner/outer Orbitals

Filling Orbital

4f ⁴

Ground State Electron Configuration

[Xe]

4f ⁴

5p ⁶

6s ²

Ground State Electron Configuration with free Orbitals (n=26)

0, 0, 0, 10, 10, 6

Ground State Electron Configuration with compressed Orbitals (n=96)

0, 0, 0, 0, 32, 64

Singularity

182

	s	p	d	f		g	h	i	j
1	2
2	2	6
3	2	6	10
4	2	6	10	4	10
5	2	6	10	14		18
6	2	6	10	14		18	22
7
8

Term Symbol

⁵I ₄

Name Derived From

The name derives from the Greek neos for "new" and didymos for "twin". It was discovered by the Swedish surgeon and chemist Carl Gustav Mosander in 1841, who called it didymium (or twin) because of its similarity to lanthanium, which he had previously discovered two years earlier.

(Nd), chemical element, rare-earth metal of transition Group IIIb of the periodic table. Neodymium is silvery-white colour and tarnishes in air to form an oxide which chips, exposing the metal to further oxidation. The metal must be sealed in a plastic covering or kept in mineral oil for preservation. It reacts gradually with cold water and rapidly with hot water to liberate hydrogen. Carl Auer von Welsbach discovered neodymium (1885) by separating ammonium didymium nitrate prepared from didymia (a mixture of rare-earth oxides) into a neodymium fraction and a praseodymium fraction by repeated crystallization. Of the rare earths, only cerium and yttrium are more plentiful than neodymium. In the igneous rocks of the Earth's crust it is more than twice as abundant as lead and about half as plentiful as copper. Neodymium occurs in the minerals monazite and bastnaesite and is a product of nuclear fission. Ion-exchange techniques have supplanted fractional crystallization for separation and purification of neodymium. The metal itself is prepared by electrolysis of the fused halides or by thermoreduction of the fluoride with calcium or lithium.

The metal is used in the electronics industry, in the manufacture of steel, and as a component in a number of alloys, among them misch metal (15 percent neodymium), used for cigarette-lighter flints. Its compounds are used in the ceramics industry for glazes and to colour glass. The crude oxide is used to counteract the green colour of iron(II) compounds in glass; and the more pure compound is used in the production of the only known glass that is bright purple in colour. This neodymium glass can be used instead of ruby as a laser material. A mixture of neodymium and praseodymium absorbs light in the region of the harmful sodium-D (spectral) lines and therefore is used in the glass of welders' and glassblowers' goggles.

Natural neodymium is a mixture of seven different isotopes: neodymium-142 (27.1 percent), neodymium-144 (23.8 percent), neodymium-146 (17.2 percent), neodymium-143 (12.2 percent), neodymium-145 (8.3 percent), neodymium-148 (5.8 percent), and neodymium-150 (5.6 percent). All are stable except the weakly radioactive neodymium-144, the lightest natural nuclide that decays by alpha emission. Two allotropes (structural forms) exist; at room temperature the structure is hexagonal close-packed. The element forms trivalent compounds such as the oxide Nd₂O₃ and the hydroxide Nd(OH)₃; the Nd³⁺ ion is stable in water. A few divalent compounds have been prepared such as the diiodide NdI₂, and the dichloride NdCl₂; the Nd²⁺ ion is unstable in aqueous solution.

APSIDIUM ©	Created:		2002-07-29		060.pdf
	Page update:		2004-12-06		060.pdf