Pr - Praseodymium

Baron von Welsbach separated the components of dydimium into neodumium (the new twin) and praseodymium (the green twin) in 1885 in Vienna. Praseodymium is a component of our glass blowing specticles.

Atomic number - 59 Density g/mL 6 .77
Atomic weight u 140 .9077 Melting point K 1204
Bonding radius A 1 .65 Boiling point K 3785
Atomic radius A 2 .67 Heat of vaporization kJ/mol 296 .8
Ionization Potential V 5 .46 Heat of fusion kJ/mol 6 .89
Electronegativity - 1 .13 Specific heat J/gK 0 .19
The oxide is mildly basic.
Crystal are hexagonal.

Electron config. : [Xe] 4f3 6s2


Isotopes of Pr: Click mass number for decay process, product for element page.


121
1.4 sec
EC,7.900 MeV
Ce-121
120.95400
124
1.2 sec
EC/ECp,11.700
Ce-124/La-123
123.94310
126
3.1 sec
EC/ECp,10.400
Ce-126/La-125
125.93526
127
4.9 sec
EC,7.500 MeV
Ce-127
126.93086
128
3.1 sec
EC/ECp,9.300
Ce-128/La-127
127.92882
129
30 sec
EC,6.300 MeV
Ce-129
128.92485
130
40.0 sec
EC,8.100 MeV
Ce-130
129.92334
131
1.53 min
EC,5.250 MeV
Ce-131
130.92002
132
1.6 min
EC,7.100 MeV
Ce-132
131.91911
133
6.5 min
EC,4.300 MeV
Ce-133
132.91619
134
17 min
EC,6.200 MeV
Ce-134
133.91569
135
24 min
EC,3.720 MeV
Ce-135
134.91313
136
13.1 min
EC,5.126 MeV
Ce-136
135.91264
137
1.28 hr
EC,2.702 MeV
Ce-137
136.91068
138
1.45 min
EC,4.437 MeV
Ce-138
137.91074
139
4.41 hr
EC,2.129 MeV
Ce-139
138.90893
140
3.39 min
EC,3.388 MeV
Ce-140
139.90907
141 100%

Stable

140.90764
142
19.12 hr
B-/EC,2.162
Nd-142/Ce-142
141.91004
143
13.57 da
B-,1.462 MeV
Nd-143
142.91081
144
17.28 min
B-,2.997 MeV
Nd-144
143.91330
145
5.984 hr
B-,1.805 MeV
Nd-145
144.91450
146
24.15 min
B-,4.200 MeV
Nd-146
145.91761
147
13.4 min
B-,2.690 MeV
Nd-147
146.91897
148
2.27 min
B-,4.930 MeV
Nd-148
147.92217
149
2.26 min
B-,3.397 MeV
Nd-149
148.92379
150
6.19 sec
B-,5.690 MeV
Nd-150
149.92699
151
18.90 sec
B-,4.100 MeV
Nd-151
150.92822
152
3.63 sec
B-,6.400 MeV
Nd-152
151.93161
153
4.3 sec
B-,5.500 MeV
Nd-153
152.93397
154
2.3 sec
B-,7.900 MeV
Nd-154
153.93805
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass