what special or unique properties does lithium have?

Answer 1

Apart from the general knowledge I could cut and paste just like anyone else:

lithium is the lightest known metal (and lithium hydride the lightest known salt).

lithium has a high capacity for capturing neutrons

otherwise it has the special properties of alkali metals.

Answer 2

Lithium (Greek lithos, “stone”), symbol Li, silvery white, chemically reactive metallic element that is the lightest in weight of all metals. In group 1 (or Ia) of the periodic table (see Periodic Law), lithium is one of the alkali metals. The atomic number of lithium is 3.

Discovery of the element is generally credited to Johann A. Arfvedson in 1817. Chemically, lithium resembles sodium in its behavior. Lithium is obtained by the electrolysis of a mixture of fused lithium and potassium chloride. It tarnishes instantaneously and corrodes rapidly upon exposure to air; when it is stored it must be immersed in a liquid such as naphtha. Lithium ranks 35th in order of abundance of the elements in Earth’s crust. It does not occur in nature in the free state but only in compounds, which are widely distributed. The metal is used as a deoxidizer and to remove unwanted gases during the manufacture of nonferrous castings. Lithium vapor is used to prevent carbon dioxide and oxygen from forming scale in furnaces in heat-treating steel. Important compounds of lithium include the hydroxide, used for bonding carbon dioxide in the ventilator systems of spacecraft and submarines; and the hydride, used to inflate lifeboats, and its heavy hydrogen (deuterium) equivalent, used in making the hydrogen bomb. Lithium carbonate, a common mineral, is used in the treatment of bipolar disorder and some forms of depression.

Lithium melts at about 181°C (about 358°F), boils at about 1342°C (about 2448°F), and has a specific gravity of 0.53. The atomic weight of lithium is 6.941.

Answer 3

1. it is a highly reactive metal
2. it reacts with air to form Li2O very readily (lithium oxide)
3. it reacts violently with water to form Li2O (shows flashes of what looks like fire and causes the water to bubble)
4. it has the capability to form a superoxide
5. it is soft enough to be cut with a knife
6. it gives off a crimson color when placed near a flame
7. it burns bright white

Answer 4

It's highly reactive. If you put it in water, it fizzes around on the top, and the heat of the reaction can be enough to ignite the hydrogen produced from the water.