Coloured Discharges
Observe coloured sparks
An electric discharge is a phenomenon arising when electric current passes through a gas. Fire off the selected discharge and watch the colour. Place the spectroscope on the marked spot and look into it. Watch the colour spectrum and search for spectral lines. You can try to identify the gas in the discharge tubes from the lines. Discharges in gases are a way of transforming a substance into a form of plasma ??“ the fourth state of matter. Discharges are known, for example, as lightning, the sodium discharge lamps of street lighting or the northern lights. The plasma differs from the standard gaseous state by the amount of free ions created from the atoms of the gas by the effect of a strong electric field.
