Uncategorized Radon is a chemical element with symbol Rn and atomic number
Chemistry in its element: End promo Meera Senthilingam This week we enter the stranger realms of chemistry as we hear the story of xenon. He could never have foreseen that his discovery would one day be used to light our roads at night, image the workings of a living lung, or propel spaceships.
The story of xenon begins in when Lord Rayleigh and William Ramsay were investigating why nitrogen extracted from chemical compounds is about one-half per cent lighter than nitrogen extracted from the air - an observation first made by Henry Cavendish years earlier.
Ramsay found that after atmospheric nitrogen has reacted with hot magnesium metal, a tiny proportion of a heavier and even less reactive gas is left over. They named this gas argon from the Greek for lazy or inactive to reflect its extreme inertness. There were no other known elements that it resembled, which led them to suspect that there was a whole family of elements yet to be discovered.
Remarkably, this turned out to be the case. The following year, Ramsay confirmed the presence in certain radioactive rocks of the lightest member of the group, helium, trapped as it was formed during the alpha-particle emission from elements such as uranium. Pushing this analogy further, it is to be expected that this element should be as indifferent to union with other elements, as the two allied elements.
In MayRamsay instructed his student Morris Travers to allow a sample of liquid air to evaporate until just a few millilitres remained. This he did, and upon examining the electrical discharge of the residue with a spectroscope, the appearance of a bright yellow line and a brilliant green line confirmed the presence of a new element.
They called it krypton, from the Greek for hidden. Realising that their missing lighter element should actually have a lower boiling point than argon, they looked again at some of the more volatile fractions of gas from liquefied atmospheric residues.
On Sunday, June 12, they prepared a sample for examination with the spectroscope, but as they turned on the current through the gas, they had no need for the prism to split the light, for the brilliant red glow of the tube confirmed the presence of the new missing element they named neon.
In an attempt to isolate more of the krypton, Ramsay and Travers repeatedly distilled out the heavier fractions of the liquefied gases. It seemed likely that this was only CO2, which is quite non-volatile at liquid air temperature. The hour was late enough to have justified neglecting this bubble of gas and going home to bed.
However, it was collected as a separate fraction. Ramsay and Travers recorded in the notebook the appearance of the spectrum from this sample: Several red lines, three brilliant and equidistant, and several blue lines were seen.
Is this pure krypton, at a pressure which does not bring out the yellow and green, or a new gas?
Ramsay and Travers wanted to name the new gas after its colour, but found that all the Greek and Latin roots indicating blue had long before been appropriated by organic chemists.
Instead, they settled on the name xenon, the stranger. It took Travers and Ramsay many months before they could isolate enough xenon to determine its density. This is not surprising since xenon is by far the least abundant of the noble gases in the atmosphere: Xenon currently finds its uses as the free element.
The most effective car headlamps currently available contain xenon gas at pressures of a couple of atmospheres. Its role is to immediately provide light on switching on before some of the other components are properly vaporised.
Being so heavy, and yet chemically inert, it is used in electrostatic ion thrusters to move satellites in space. Atoms of xenon are ionised, then accelerated to speeds of around 30 kilometres per second before being flung out the back of the engine.Radon levels in groundwater are fairly high, but usually radon is quickly released into air as soon as the groundwater enters surface waters.
Exposure to high levels of radon through breathing air is known to cause lung diseases. Radon is an element that is on the periodic table of elements.
It is a member of the family called the noble gases, which is group number Radon is a gas. It is a gas at k. it is the heaviest known mononuclear gas at that temperature. Radon is also colorless. When it is cooled below. Nov 20, · It is the only radioactive caninariojana.com is a chemical element in the periodic table that has the symbol Rn and atomic number A radioactive noble gas that is formed by the disintegration of radium, radon is one of the heaviest gases and is considered to be a health caninariojana.com: Resolved.
A thorough understanding of its physical, chemical and nuclear properties are required for its effective use as an environmental tracer.
For example, the radon partition coefficient between water and air and the octanol-water partition coefficient (K ow) are reported to be and , respectively. This WebElements periodic table page contains physical properties for the element radon. Introduction to Radon Transforms The Radon transform represents a function on a manifold by its integrals over certain submanifolds.
Integral transformations of this kind have a wide range of applications.