1. Copper has a metallic structure, consisting of a lattice of positively charged copper ions surrounded by a "sea" of delocalized electrons that move freely throughout the lattice. This arises because copper atoms have only one valence electron each, located in the outermost "s" orbital, which is easily ionized. When many copper atoms are brought together, they lose these valence electrons to form positively charged ions, which are held together by the electrostatic attraction between the ions and the electrons surrounding them.
2. An alloy of copper is harder than pure copper because it contains other elements that introduce imperfections in the lattice structure of the metal, making it more difficult for the atoms to slide past each other when subjected to external forces. These imperfections can take the form of either interstitial or substitutional defects. In interstitial alloying, smaller atoms, such as carbon or nitrogen, are introduced into the lattice in the spaces between the copper atoms. This creates stress in the lattice, making it more difficult for the copper atoms to move past each other. In substitutional alloying, other metals, such as zinc, nickel, or silver, are added to replace some of the copper atoms, forming a new lattice structure. The different sizes and electronegativities of these atoms can introduce stresses and imperfections in the crystal structure, contributing to increased hardness.
1. copper is a metal. describe the structure and bonding of copper
2. copper can be alloyed with other elements to make it harder. explain why an alloy of copper is harder than pure copper.
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