Answer:
Copper (cu)
Explanation:Copper (Cu), chemical element, a reddish, extremely ductile metal of Group 11 (Ib) of the periodic table that is an unusually good conductor of electricity and heat. Copper is found in the free metallic state in nature. This native copper was first used (c. 8000 BCE) as a substitute for stone by Neolithic (New Stone Age) humans.
. Metallurgy dawned in Mesopotamia as copper was cast to shape in molds (c. 4000 BCE), was reduced to metal from ores with fire and charcoal, and was intentionally alloyed with tin as bronze
atomic number 29
atomic weight 63.546
melting point 1,083 °C (1,981 °F)
boiling point 2,567 °C (4,653 °F)
density 8.96 at 20 °C (68 °F)
valence 1, 2
electron configuration 2-8-18-1 or (Ar)3d104s1
Copper is one of the most ductile metals, not especially strong or hard. Strength and hardness are appreciably increased by cold-working because of the formation of elongated crystals of the same face-centred cubic structure that is present in the softer annealed copper.