1) Lithium is the third element on the periodic table and is denoted by the atomic symbol Li. It has an atomic number of 3 and an atomic mass of 6.94 unified atomic mass units.
Lithium is a solid at standard temperature and pressure (STP), with a melting point of 180.54 �C and a boiling point of 1342 �C. It has a mass density of 0.535 g/cm^3 and a sound speed of 6000 m/s. Its thermal conductivity is 85 W/(m K).
In terms of electromagnetic properties, lithium is a conductor and paramagnetic, with a resistivity of 9.4�10^-8 ? m. It is silver in color.
Lithium is a reactive element with a valence of 1, an electronegativity of 0.98, an electron affinity of 0.618 eV, and a first ionization energy of 5.391 eV.
The atomic radius of lithium in its electronic ground state is 145 picometers.
Lithium is the 44th most abundant element in the universe and the 34th most abundant in the Earth's crust. It is the 36th most abundant element in the human body.
Lithium has two stable isotopes: Li-7 (92.41%) and Li-6 (7.59%). It also has unstable isotopes, including Li-8, which has a half-life of 839.9 milliseconds.
The CAS number for lithium is 7439-93-2 and its PubChem CID number is CID3028194.