hydrogen bonding that contributes to the high boiling point of water compared to similar molecules that are not involved with this type of bonding. Hydrogen bonding is involved with protein and DNA molecules in living things. It is what gives DNA its double helical shape. This type of bonding is what makes the characteristics of polymers like plastic and nylon molecules. Hydrogen bonding increases water solubility, increases the boiling point, and increases the melting point. It accounts for the high surface tension of water.
BONDING IN METALS Metallic bonding has briefly been discussed. It involves the sharing of multiple valence electrons between many metallic (so called positively-charged) ions. The electrons form the glue that connects the different metal atoms together and gives metals their structure. Metallic bonding is different from all other types of bonding already discussed. It is based on the fact that metals have a low ionization energy and is why these have high melting and boiling points. The freedom of the electrons in this “soup” means that electrons can have energy pass through them in the form of electric currents. This makes just metals, graphite, and ionic compounds the only things that can conduct electricity. Metals can also conduct heat faster than other molecules. Metals will have a minimum of one valence electron that isn’t shared per se. Instead, the outer atomic orbitals will overlap, leading to something similar to covalent bonding. One exception to the typical metallic bonding seen in metals is that of mercury or Hg2+ molecules that form covalent bonds with other mercury ions. This accounts for the different properties of mercury when compared to other metals. Alloys represent solutions of different types of metals.
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