Lithium is a soft, silver-white metal that belongs to the alkali metals. These are the elements in the first column of the periodic table.
Lithium is represented by the symbol “Li”, and it has the atomic number 3. It has three protons and, usually, four neutrons in its nucleus. It has three electrons.
Lithium is the lightest metal and the least dense element which is solid under normal conditions. Like all alkali metals, lithium is highly reactive, corroding quickly in moist air to form a black tarnish. For this reason, lithium metal is typically stored in oil. When cut open, lithium exhibits a metallic lustre, but contact with oxygen quickly turns it back to a dull silvery grey colour. Lithium in its elemental state is highly flammable.
Lithium is mixed (alloyed) with aluminium and magnesium for light-weight alloys. One important use is in some sorts of cells and batteries. The tiny button cell batteries often used in watches and calculators are litium cells. Lithium is also used in rechargeable lithium-ion batteries, which are used in some vehicles and consumer electronics. Lithium is also used in making,some greases, heat resistant glass,and it has also been used in medicine. In medicine it has been used as a treatment for depression, or for bipolar disorder.