Periodic
Table
|
Lanthanum
|
Symbol
|
La
|
|
Atomic
Number
|
57
|
Relative
Atomic
Mass
12C
=
12.0000
|
138.9055(2)
[Since
1985]
|
|
Atomic
Radius
pm
|
188
|
First
Ionisation
Energy
kJ
mol-1
|
538.1
|
|
Electronegativity
|
1.10
|
|
Density
kg
m-3
|
6145
[298
K]
|
|
Molar
Volume
cm3
|
22.60
|
Thermal
Conductivity
W
m-1
K-1
|
13.5
[300
K]
|
|
Melting
Point
K
|
1194
|
|
Boiling
Point
K
|
3730
|
|
Number
of
Isotopes
|
26
|
|
Isotope
Atomic
mass/u
Mole
fraction
|
138La
137.907
108(4)
0.000
90(1)
139La
138.906
349(4)
0.999
10(1)
|
|
Inner/outer
Shells
|
|
|
Inner/outer
Orbitals
|
|
|
|
|
???
|
Algorythm
of
Software
|
|
![[Picture]](057_ga.jpg)
|
|
|
|
|
Distribution
of
electrons
|
|
|
s
|
p
|
d
|
f
|
|
1
|
2
|
|
|
|
|
2
|
2
|
6
|
|
|
|
3
|
2
|
6
|
10
|
|
|
4
|
2
|
6
|
10
|
|
|
5
|
2
|
6
|
1
|
|
|
6
|
2
|
|
|
|
|
7
|
|
|
|
|
|
|
|
s
|
p
|
d
|
f
|
|
1
|
2
|
|
|
|
|
2
|
2
|
6
|
|
|
|
3
|
2
|
6
|
10
|
|
|
4
|
2
|
6
|
10
|
1
|
|
5
|
2
|
6
|
|
|
|
6
|
2
|
|
|
|
|
7
|
|
|
|
|
|
|
Filling
Orbital
|
|
|
|
|
Ground
State
Electron
Configuration
|
|
|
|
|
|
|
Ground
State
Electron
Configuration
w
ith
free
Orbitals (n=29)
|
|
|
|
![[Picture]](057_fr.jpg)
|
![[Picture]](057_fa.jpg)
|
|
|
|
Ground
State
Electron
Con
figuration
with
compressed
Orbitals (n=96)
|
|
|
|
![[Picture]](057_cr.jpg)
|
![[Picture]](057_ca.jpg)
|
|
|
|
Singularity
|
|
|
|
|
|
s
|
p
|
d
|
f
|
g
|
h
|
i
|
j
|
|
1
|
2
|
|
|
|
|
|
|
|
|
2
|
2
|
6
|
|
|
|
|
|
|
|
3
|
2
|
6
|
10
|
|
|
|
|
|
|
4
|
2
|
6
|
10
|
1
|
13
|
|
|
|
|
|
5
|
2
|
6
|
10
|
14
|
18
|
|
|
|
|
6
|
2
|
6
|
10
|
14
|
18
|
22
|
|
|
|
7
|
|
|
|
|
|
|
|
|
|
8
|
|
|
|
|
|
|
|
|
|
|
|
|
Term
Symbol
|
2D
3/2
|
Name
Derived
From
and
Discovery
|
The
name
derives
from
the
Greek
lanthanein
for
"
to
be
hidden
or
to
escape
notice"
because
it
hid
in
cerium
ore
and
was
difficult
to
separate
from
that
rare
earth
mineral.
It
was
discovered
by
the
Swedish
surgeon
and
chemist
Carl-Gustav
Mosander
(Stockholm,
Sweden)
in
1839.
In
1842,
Mosander
separated
his
lanthanium
sample
into
two
oxides;
for
one
of
these
he
retained
the
name
lanthanum
and
for
the
other
he
gave
the
name
didymium
(or
twin).
|
|
![[Picture]](../images/aglarule.gif){kind=small}
