Covalent and Metallic Bonds
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Transcript of Covalent and Metallic Bonds
Covalent and Metallic Bonds
How are these two items different?
Covalent bonds Metallic bonds
Covalent Bonds
Most things are held together with covalent bonds.
Characteristics• Usually low melting points• Brittle in solid state
Ex: Oxygen• low boiling point
• Gas at room temperature.
Ex: Wood: Brittle
Covalent BondAtoms share one or more electronsNonmetals need energy to transfer electrons, so 2 nonmetals
will not transfer electrons but share them to fill the valence shells.
Covalent Bonds and Molecules Substances made form covalent bonds consist of individual particles
called molecules. A molecule consists of two or more atoms joined in a definite ratio. Most molecules are composed two or more elements- like water.
Electron Dot One way to represent atom and molecule bonding is with an
electron-dot diagram The diagram only shows the valence electrons of an atom.
• Can help you predict how an atom may bond
Covalent Compounds and Molecules An atom is to an element
AsA molecule is to a compound
Simplest Molecules
The simplest molecules contain 2 bonded atoms Diatomic
The elements Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, and Bromine are always found as diatomic molecules:
More complex Molecules
Soap, plastic,& proteins are all complex molecules. Carbon is the base for a lot of these because it has a valence shell
of 4.
Metallic Bonds Metals can be shaped because of metallic bonds.
A metallic bond is formed by the attraction between positive charged metal ions and the electrons in the metal.
The positive ions form as the metals lose electrons.
Movement of Electrons throughout a Metal
Bonding in metals happens because the atoms are so close the outer energy shells overlap. This allows the valence electrons to “travel”
throughout the metal
Properties of metals
Explain what each of the following are: Conductivity
Ductility Malleability
Why can metals be bent without breaking?