Element with the atomic number of 51
Antimony (chemical symbol - Sb, from Lat. Stibium) is a chemical element of the 15th group (according to the outdated classification - the fifth group of the main subgroup, VA) of the fifth period of the periodic system of chemical elements of D. I. Mendeleev; has the atomic number 51.
A simple substance antimony is a semi-metal of silvery-white color with a bluish tinge, coarse-grained structure. Four metallic allotropic modifications of antimony are known to exist at different pressures, and three amorphous modifications (explosive, black and yellow antimony).