Curium
Definition and meaning of Curium in chemistry.
![Curium element card: symbol Cm, atomic number 96, atomic mass [247], electron configuration [Rn] 5f⁷ 6d¹ 7s², oxidation states +3, Actinide, f-block, period 7, solid at room temperature.](/assets/images/terms/curium-chemical-element.webp)
Curium is a synthetic transuranic element with the symbol Cm and atomic number 96. A transuranic element is an artificially created element with an atomic number greater than 92. Curium is a highly radioactive, hard, silvery metal. Scientists named this element in honor of the pioneering physicists Marie and Pierre Curie.
In more detail
Curium is a highly radioactive actinide element. Actinides form a group of heavy, radioactive metals at the bottom of the periodic table. Curium rapidly oxidizes in air to form a thin surface layer.
Scientists synthesize this element in nuclear reactors and large particle accelerators. They achieve this by bombarding lighter elements like plutonium or americium with neutrons or alpha particles. An alpha particle is a helium nucleus consisting of two protons and two neutrons.
In its chemical compounds, curium strongly favors the +3 oxidation state. This behavior aligns its chemistry closely with gadolinium, its counterpart in the lanthanide series. Because of its specific electron arrangement in the f-block, curium displays unique magnetic properties.
The solid metal transitions to an antiferromagnetic state at very low temperatures. In an antiferromagnetic material, neighboring atoms align their magnetic moments in completely opposite directions. Furthermore, the extreme radioactivity of curium generates massive amounts of decay heat.
This intense thermal energy actually causes the pure metal to glow with a purple light in the dark.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Cm |
| Atomic number | 96 |
| Atomic mass | [247] u |
| Category | Actinide |
| Year discovered | 1944 |
Curium-244 serves as a reliable alpha particle source on multiple NASA Mars rovers. It provides the essential radiation for the alpha particle X-ray spectrometers on these rovers. Scientists use these advanced instruments to determine the precise elemental composition of Martian rocks and soils. This data helps researchers understand the geological history of the red planet.
Frequently asked questions
Why does curium glow in the dark?
The curium isotopes emit intense alpha radiation. This radiation excites the surrounding air molecules and the metal itself. This process produces visible thermal and radioluminescent light.
Is curium useful for generating nuclear power?
Curium isotopes generate significant heat. However, engineers do not typically use them for power generation. Their intense neutron and gamma emissions create major safety hazards.
Related terms
Sources & references
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