Curium (Cm)
Isotopes of Curium
| Isotope | Atomic Mass | Half-life | Mode of Decay | Nuclear Spin | Nuclear Magnetic Moment |
| Cm-240 | 240.05552 | 27 hours | α to Pu-236; EC to Am-240; SF |
0 | No data available |
| Cm-241 | 241.05765 | 32.80 days | α to Pu-237; EC to Am-241 |
1/2 | No data available |
| Cm-242 | 242.05883 | 162.80 days | α to Pu-238; SF |
0 | No data available |
| Cm-243 | 243.06138 | 28.50 years | α to Pu-239; EC to Am-243 |
5/2 | 0.41 |
| Cm-244 | 244.06275 | 18.11 years | α to Pu-240; SF |
0 | No data available |
| Cm-245 | 245.06548 | 8500 years | α to Pu-241; SF |
7/2 | No data available |
| Cm-246 | 246.06722 | 4780 years | α to Pu-242; SF |
0 | No data available |
| Cm-247 | 247.070347 | 1.56 x 107 years | α to Pu-243 | 9/2 | 0.37 |
| Cm-248 | 248.07234 | 3.40 x 105 years | α to Pu-244; SF |
0 | No data available |
| Cm-249 | 249.07595 | 64.15 minutes | ß- to Bk-249 | 1/2 | No data available |
| Cm-250 | 250.07835 | 9700 years | α to Pu-246; ß- to Bk-250; SF |
0 | No data available |
Curium is a radioactive rare earth metal. It was first produced in 1944 in a cyclotron at the University of California, Berkeley, USA, by Glenn T. Seaborg, Ralph A. James and Albert Ghiorso, who bombarded Plutonium-239 with α-particles. It takes its name from that of Pierre and Marie Curie, who were known for their research on radioactivity.
Curium is a hard, brittle, radioactive silvery metal. It is paramagnetic in ambient conditions and becomes antiferromagnetic when it cools. It oxidizes readily. It forms strongly fluorescent complexes with various organic compounds. It does not occur in nature and must be made in a nuclear reactor by neutron capture reactions from plutonium and americium isotopes. It tarnishes slowly in dry air at room temperature. The most stable isotope is Curium-247, which has a half-life of almost 16 million years.
All known isotopes of curium are radioactive. When introduced into the human body, curium accumulates in the bones, lungs and liver, promoting cancer.
Properties of Curium
| Name | Curium |
| Symbol | Cm |
| Atomic number | 96 |
| Atomic weight | [247] |
| Standard state | Solid at 298 °K |
| CAS Registry ID | 7440-51-9 |
| Group in periodic table | N/A |
| Group name | Actinoid |
| Period in periodic table | 7 (Actinoid) |
| Block in periodic table | f-block |
| Color | Silver |
| Classification | Metallic |
| Melting point | 1613 °K [or 1340 °C or 2444 °F] |
| Boiling point | 3383 °K [or 3110 °C or 5630 °F] |
| Density of solid | 13.51 g/cm3 |
| Electron configuration | [Rn]5f76d17s2 |
