Periodic Table

Curium

Actinide

Quick Facts about Curium

Am
  • solid- state of matter at room temperature
  • Radioactive- no stable isotopes exist
  • +3- common oxidation states in compounds
Bk

Curium (Cm) is element 96 on the periodic table. Atomic mass of Cm: 247.0000 u. Cm is in period 7. Melting point of Cm: 1613.00 K.Density of Cm: 13.51 g/cm³.

Why Curium Matters

Curium in everyday life and industry

In Your Home

  • Mars rovers have used curium for analyzing rock composition
  • Pacemaker power sources have considered curium
  • Very limited commercial applications

Industry Uses

SpaceAlpha particle spectrometers for space missions use curium-244

In Your Body

✗ Not essential

Accumulates in bones. No biological role.

Safety: Curium is radioactive and highly toxic. Ingestion or inhalation is extremely dangerous.

Discovery of Curium

Discovered by G.T.Seaborg, R.A.James, A.Ghiorso in United States, 1944

Name origin: Named in honor of Pierre and Marie Curie.

History & Events

1944
Named after Marie and Pierre Curie
1944
Discovered by Seaborg, James, and Ghiorso in 1944
1944
Classified until after WWII
1944
Seaborg announced it on a radio quiz show for children

About Curium

Radioactive metallic transuranic element. Belongs to actinoid series. Nine known isotopes, Cm-247 has a half-life of 1.64*10^7 years. First identified by Glenn T. Seaborg and associates in 1944, first produced by L.B. Werner and I. Perlman in 1947 by bombarding americium-241 with Neutrons. Named for Marie Curie.

Atomic Properties of Cm

Atomic Number of Cm
96
Atomic Mass of Cm
247.0000 u
Electron Configuration
[Rn] 5f7 6d1 7s2
Electronegativity
1.28
Block
f-block
Group
Period
7

Physical Properties of Cm

Phase (STP)
solid
Melting Point of Cm
1613.00 K
Boiling Point of Cm
3383.00 K
Density of Cm
13.5100 g/cm3

Atomic Radii

Covalent
166 pm
Van der Waals
245 pm

Common Misconceptions

Wrong:Curium's discovery was announced through normal scientific channels.
Correct:Glenn Seaborg announced curium's existence on a children's radio quiz show ('Quiz Kids') before formal publication.
Wrong:Curium is named only after Marie Curie.
Correct:The element honors both Marie and Pierre Curie for their pioneering work on radioactivity.
Wrong:Curium has no practical applications.
Correct:Cm-244 powers alpha particle X-ray spectrometers on Mars rovers for analyzing rock composition.

Isotopes of Curium

Curium has 0 naturally occurring isotopes, plus 7 notable radioactive isotopes.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
24296Cm (Cm-242)Curium-242 isotope242.05883580%162.8 daysα
24396Cm (Cm-243)Curium-243 isotope243.0613893
24496Cm (Cm-244)Curium-244 isotope244.0627528
24596Cm (Cm-245)Curium-245 isotope245.0654915
24696Cm (Cm-246)Curium-246 isotope246.0672238
24796Cm (Cm-247)Curium-247 isotope247.0703541
24896Cm (Cm-248)Curium-248 isotope248.0723499

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Curium have important real-world applications in science and industry.

Industrial Applications

244Cm and 242Cm (with half-lives of 18.1 years and 163 days, respectively) are strong alpha emitters (see alpha decay). The alpha emission from these isotopes creates a considerable quantity of heat that makes them useful as alpha particle sources, as well as heat generators in RTGs (radioisotopic thermoelectric generators) [75]. During a number of space missions based in America and Europe, 244Cm was the source used for the alpha particle X-ray spectrometer that was on board vehicles such as the Mars Exploration Rover and the Rosetta/Philae [75], [618]. 244Cm has a large neutron capture to neutron fission cross-section ratio and has been used in a nuclear reactor to produce higher mass radio-isotopes of curium (Fig. IUPAC.96.1) [75], [618].

Uses

It has no significant commercial applications.

Sources

Made by bombarding plutonium with helium ions. So radioactive it glows in the dark.

Geochemistry

Goldschmidt
synthetic

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