Absolutely everything you need to know about the ATOM ... and much much MORE!
Hannah's ATOM UNIVERSE
Chemistry? more like che-MYSTERY? don't worry you have come to the right place!
Magnesium Sulphate Emission Spectra
Copper Carbonate Emission Spectra
Calcium Chloride Emission Spectra
Sodium Chloride Emission Spectra
Absorption, emission and continuous spectra
There are three main kinds of SPECTRUMS
A CONTINUOUS SPECTRUM is produced when a white hot metal object (for example an incandescent light bulb filament) emits the fulll range of wavelenghts, this spectrum consists fo alll of the colours of the rainbow, ranging from red to violet.
An EMISSION SPECTRUM is produced when a pure gaseous element (for example, hydrogen) is exposed to an electrical discharge which causes the gas to glow and emit radiation. The emission spectra produced subsequent to this is made up of a series of lines against a dark background.
An ABSORPTION SPECTRUM is produced when a cloud of cold gas is put in between a hot metal and a detector; subsequent to this the spectrum is viewed. It is made up of a black background against which there is a pattern of lines. Furthermore, the atoms which are gaseous absorb specific wavelengths of light which origniate from the continuous spectrum. (figure 1)
Figure 1 - The Different Spectrums
The line emission spectrum of hydrogen provides EVIDENCE for the existence of electrons in discrete energy levels; which get closer together (they are said to converge) at higher energies. At the limit of this convergence the lines merge forming a continum. Beyond this contiuum the electron can have any energy it is no longer undert he influence of the nucleus and is therefore oustide the atom. Such an electron may be referred to as a free electron.
Atomic Spectroscopy
Flame test? why everyone knows what that is? its more of a competition really- a competition to see which flame can shine the brightest!
JUST JOKING! of COURSE that's not what it means! (though it is quite an interesting concept....)
Flame tests ACTUALLY are experiments which are conducted in a laboratory environment. The purpose/ reasoning behind the flame test, is to observe teh colours emitted due to the excited electrons falling from higher energy levels to lower energy levels; when this happens photons of light are emitted. The lights emitted also are dependent on the element- this is also useful for discovering substances which are not known.
Flame tests
Lithium is the first one
Lithium is able to emit two colours. When it is placed first over the flame it emits a crimson colour. However, when it continues to burn for a longer period of time, the colour changes to white. Lithium is also an univalent element.
