Tl - Thallium

The toxic heavy metal thallium was discovered in 1861 by Crookes in London.

Atomic number - 81 Density g/mL 11 .85
Atomic weight u 204 .37 Melting point K 577
Bonding radius A 1 .48 Boiling point K 1746
Atomic radius A 2 .08 Heat of vaporization kJ/mol 164 .1
Ionization Potential V 6 .108 Heat of fusion kJ/mol 4 .142
Electronegativity - 2 .04 Specific heat J/gK 0 .13
The oxide is mildly basic.
Crystal are hexagonal.

Electron config. : [Xe] 4f14 5d10 6s2 6p1


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


179
0.16 sec
a,6.860 MeV
Au-175
178.99165
179a
1.4 msec
a,6.860 MeV
Au-175
178.99165
180
1.9 sec
a/EC/ECF,6.258
Au-176/Hg-180/?
179.99023
181
3.4 sec
EC,8.500 MeV
Hg-181
180.98690
182
3.1 sec
a/EC,10.100
Au-178/Hg-182
181.98561
183
6.9 sec
EC,7.600 MeV
Hg-183
182.98260
183a
60 msec
a,6.850 MeV
Au-179
182.98314
184
11 sec
a/EC,9.200
Au-180/Hg-184
183.98174
185
19.5 sec
a/EC,6.600
Au-181/Hg-185
184.97906
186
27.5 sec
a/EC,8.500
Au-182/Hg-186
185.97852
187
51 sec
a/EC,5.900
Au-183/Hg-187
186.97616
188
71 sec
EC,7.800 MeV
Hg-188
187.97592
189
2.3 min
EC,5.180 MeV
Hg-189
188.97369
190
2.6 min
EC,7.000 MeV
Hg-190
189.97380
191

EC,4.490 MeV
Hg-191
190.97188
192
9.6 min
EC,6.120 MeV
Hg-192
191.97214
193
21.6 min
EC,3.640 MeV
Hg-193
192.97055
194
33.0 min
a/EC,5.280
Au-190/Hg-194
193.97105
195
1.16 hr
EC,2.810 MeV
Hg-195
194.96965
196
1.84 hr
EC,4.380 MeV
Hg-196
195.97050
197
2.84 hr
EC,2.180 MeV
Hg-197
196.96953
198
5.3 hr
EC,3.460 MeV
Hg-198
197.97046
199
7.42 hr
EC,1.440 MeV
Hg-199
198.96981
200
26.1 hr
EC,2.456 MeV
Hg-200
199.97094
201
72.912 hr
EC,1.275 MeV
Hg-201
200.97080
202
12.23 da
EC,1.364 MeV
Hg-202
201.97209
203 29.524%

Stable

202.97232
204
3.78 yr
B-/EC,3.800
Pb-204/Hg-204
203.97384
205 70.476%

Stable

204.97441
206
4.199 min
B-,1.533 MeV
Pb-206
205.97609
207
4.77 min
B-,1.423 MeV
Pb-207
206.97740
208
3.053 min
B-,5.001 MeV
Pb-208
207.98200
209
2.20 min
B-,3.980 MeV
Pb-209
208.98534
210
1.30 min
B-/B-n,5.484
Pb-210/Pb-209
209.99006
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass