Basic Information

Name: Antimony 
Symbol: Sb 
Atomic Number: 51 
Atomic Mass: 121.76 amu 
Melting Point: 630.0 °C (903.15 K, 1166.0 °F) 
Boiling Point: 1750.0 °C (2023.15 K, 3182.0 °F) 
Number of Protons/Electrons: 51 
Number of Neutrons: 71 
Classification: Metalloid 
Crystal Structure: Rhombohedral 
Density @ 293 K: 6.684 g/cm3 
Color: bluish
Date of Discovery: Known to the ancients 
Discoverer: Unknown 
Name Origin: From the Greek words anti (opposed) and monos (solitude), hence "not alone" 
Symbol Origin: From stibium, the ancient name for antimony sulfide 
Uses: hardens lead, plastics, chemicals 
Obtained From: stibnite, valentinite