Chemistry Nexus
by WebElements: the periodic table on the web
X-ray study of the alkali metals at low temperatures
Cold working of sodium metal converts body centred sodium metal to a mixture of a hexagonal form and body centred sodium at 5 K. The hexagonal from converts back to the body-centred form at 100-100 K.Cold working of lithium metal converts body centred lithium metal to a mixture of a hexagonal form and body centred lithium at 78 K.
Potassium, rubidium, and caesium retain their body centred structure after cooling.
WebElements December 24th, 2009
Posted In: Chemistry, Crystallography, Group 1 elements
Does ET have the street lights on?
Scientists crossed a new frontier in exo-planet research just last year when, using the Hubble Space Telescope, they detected sodium by its characteristic orange colour in the atmosphere of a large alien world orbiting the star HD 209458. Perhaps we are seeing ETs street lighting from a distance?
Beginning in 2006, a new telescope, Kepler (approved recently by NASA) will monitor about 100,000 nearby stars, searching for the slight dimming that occurs when an orbiting planet blocks some of the parent star’s light.
WebElements December 8th, 2009
Posted In: Analytical chemistry, Atmospheric chemistry, Chemistry
Tags: Sodium