Conduct heat and electricity well electrons are delocalized and free to move Are malleable and ductile the cations are more free to move relative to each other than in ionic solids Are shiny 'lustrous' and good conductors of heat. They are only formed by nonmetals, that can form covalent bonds Because all atoms are covalently bonded, they have extremely high melting points.
Three-dimensional network covalent solids are extremely hard and brittle. Structure and bonding in metals Metallic bonding Metals consist of giant structures of atoms arranged in a regular pattern. A model showing how metallic bonds are formed - the first diagram shows the outer electrons in their atoms, and the second diagram shows that the electrons have become delocalised Properties of metals The structure and bonding of metals explains their properties : they are electrical conductors because their delocalised electrons carry electrical charge through the metal they are good conductors of thermal energy because their delocalised electrons transfer energy they have high melting points and boiling points , because the metallic bonding in the giant structure of a metal is very strong - large amounts of energy are needed to overcome the metallic bonds in melting and boiling Question Explain why metals can conduct electricity.
In this scenario, the surplus of electrons from the n-type semiconductor and the deficiency in electrons from the p-type semiconductor combine to create a depletion region. In this state, the system is said to be at equilibrium. Combining n-type and p-type semiconductors creates a system which has useful applications in modern electronics. Forward Biased p-n Junction : If the cathode of a battery is connected to the p-type semiconductor while the anode is connected to the n-type semiconductor, the system is said to be forward biased and current flows through the junction.
Reverse Biased p-n Junction : If the battery anode is connected to the p-type semiconductor and the cathode connected to the n-type semiconductor, the system is said to be reverse biased and negligible current passes.
Electronic devices and instruments, such as digital alarm clocks, mp3 players, computer processors, and the electronics in cell phones, all take advantage of semiconductor technology. Doping provides a way to modulate the properties of semiconductors that have broad applications in daily life.
Privacy Policy. Skip to main content. Liquids and Solids. Search for:. Crystals and Band Theory Bonding in Metals: The Electron Sea Model Metallic bonding may be described as the sharing of free electrons among a lattice of positively charged metal ions. Learning Objectives Describe the electron sea model of metallic bonding. Key Takeaways Key Points Many of the unique properties of metals can be explained by metallic bonds.
Metallic bonds can occur between different elements to form an alloy. In contrast to electrons that participate in both ionic and covalent bonds, electrons that participate in metallic bonds delocalize, forming a sea of electrons around the positive nuclei of metals.
Key Terms metallic bond : A chemical bond in which mobile electrons are shared over many nuclei; this leads to electrical conduction. Doping: Connectivity of Semiconductors The process of adding substances to a pure semiconductor for the purposes of modulating its electrical properties is known as doping. Metals conduct electricity and heat very well because of their free-flowing electrons. As electrons enter one end of a piece of metal, an equal number of electrons flow outward from the other end.
When light is shone on to the surface of a metal, its electrons absorb small amounts of energy and become excited into one of its many empty orbitals. The electrons immediately fall back down to lower energy levels and emit light. This process is responsible for the high luster of metals. The American Platinum Eagle is the official platinum bullion coin of the United States and was first minted in The luster of a metal is due to its metallic bonds. Recall that ionic compounds are very brittle.
Application of a force results in like-charged ions in the crystal coming too close to one another, causing the crystal to shatter.
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