Americium

Americium:

Image of ionization smoke detector which use a small amount of Americium-241 to detect smoke 

Facts about Americium:

• Nickel: Americium is a soft, shiny, silvery-white radioactive actinide.
• Fun fact about Americium: In ionization smoke detectors, Americium is used as the source alpha particles.  Alpha particles are used to ionize the air molecules creating negatively and positively charged particles.  There is a constant flow of the charged particles inside the smoke detector and when broken by smoke, the alarm is triggered. 
• Chemical symbol: Am
• Atomic number: 95

A crystal structure containing Americium:

Image of Americium complex (Americium shown in blue) 

Facts about this structure:

• Formula: Cs ⁺,C₂₀ H₄ Am F₂₄ O₈ ^-
• Structure name: Cesium tetrakis(hexafluoroacetylacetonato)-americium(iii)
• Fun fact about the structure: This structure (CsAm(HFA)₄) is isomorphous (same crystal structure) as a complex containing Yttrium (CsY(HFA)₄) and a complex comtaining Europium (CsEu(HFA)₄)
• CSD refcode: CAMHFA (What's this?)
• Associated publication: J.H.Burns, M.D.Danford, Inorganic Chemistry,  1969, 8, 1780, DOI: 10.1021/ic50078a048

More info:

Americium is a synthetic radioactive element.  It is located below Europium which is named after Europe so by analogy it was named Americium after the Americas.  It is used in several different ways including in ionization smoke detectors, a neutron source in industrial gauges and it's possible for it to be used in nuclear batteries or as fuel for space ships with nuclear propulsion.  When it is first prepared, it has a silvery white appearance but then slowly tarnishes when exposed to air because it reacts with oxygen.  Since it is a highly radioactive element that emits alpha particles, it is harmful to life and it has been proposed to use bacteria and fungi to "remove" it from the environment. 

More info about the International Year of the Periodic Table (IYPT) in crystals project:

This project (#IYPTCrystals) is part of the International Year of the Periodic Table celebration (#IYPT2019), read more about the project here. You can follow us on social media using #IYPTCrystals and learn more about the wonders of crystals by following the CCDC on Twitter @ccdc_cambridge on Facebook ccdc.cambridge, on Instagram ccdc_cambridge or on YouTube CCDCCambridge.

If you want to find out more about some of the terms and concepts we have a Frequently Asked Questions Page.

A visualisation showing the structure containing Americium alongside other structures published in the same scientific article: