Question

Is copper ductile or brittle?

Answer 1

We know that materials which are ductile can be drawn into wires by stretching and show deformation easily and are mainly affected by temperature whereas brittle materials crack or break easily, do not show deformation and are mainly affected by pressure (or stress). We can easily identify whether the given material is ductile or brittle by knowing its physical properties.

Complete answer:
Metals are one of the most malleable and ductile materials in the universe because of the presence of electronically charged particles which freely move around their atom. Basically the metals tend to form metallic bonds in which the valence electrons from the s and p orbitals delocalized and form a sea of electrons which surrounds the positively charged ions or nuclei of the interacting metal ions.
When a metal has these kinds of electrons, then they are highly malleable and ductile because the atoms are able to easily slide over each other into new positions without breaking the metallic bond that means the local bonds can be easily broken and reformed within a metallic bond.
If a small stress is put onto the metal, then the layers of atoms will tend to roll over each other and if the stress is released, then the atoms will fall back to their original positions. Thus, the metals are said to be elastic.
We know that copper is a metal and thus, we can conclude that copper is ductile and malleable.

Note:
Remember that metallic bonds are mediated by strong attractive forces and thus contribute to most of the properties of metals like low volatility, high melting and boiling points, high density, electrical conductivity, lustrous nature of metals, etc.