covalent network solid

Examples of covalent network solid in the following topics:

• Covalent Crystals

  • Atoms in covalent solids are covalently bonded with their neighbors, creating, in effect, one giant molecule.
  • Covalent solids are a class of extended-lattice compounds in which each atom is covalently bonded to its nearest neighbors.
  • Similarly, a covalent solid cannot "melt" in the usual sense, since the entire crystal is one giant molecule.
  • Another property of covalent network solids is poor electrical conductivity, since there are no delocalized electrons.
  • These two allotropes of carbon are covalent network solids which differ in the bonding geometry of the carbon atoms.

• Covalent Bonds

  • Covalently sharing two electrons is also known as a "single bond."
  • Covalently sharing two electrons is also known as a "single bond."
  • Covalent bonding interactions include sigma-bonding (σ) and pi-bonding (π).
  • Ionic solids are generally characterized by high melting and boiling points along with brittle, crystalline structures.
  • Covalent compounds, on the other hand, have lower melting and boiling points.

• Comparison between Covalent and Ionic Compounds

  • Covalent bonds are characterized by the sharing of electrons between two or more atoms.
  • At room temperature and normal atmospheric pressure, covalent compounds may exist as a solid, a liquid, or a gas, whereas ionic compounds exist only as solids.
  • Although solid ionic compounds do not conduct electricity because there are no free mobile ions or electrons, ionic compounds dissolved in water make an electrically conductive solution.
  • Therefore, they have higher melting and boiling points compared to covalent compounds.
  • Identify element pairs which are likely to form ionic or covalent bonds

• Molecular Crystals

  • Molecules held together by van der Waals forces form molecular solids.
  • Covalent bonding implies that the forces acting between atoms within the molecule (intramolecular) are much stronger than those acting between molecules (intermolecular), The directional property of covalent bonding gives each molecule a distinctive shape which affects a number of its properties.
  • Whereas the characteristic melting point of metals and ionic solids is ~1000 °C, most molecular solids melt well below ~300 °C.
  • However, they can convert into covalent allotropes having atomic chains extending all through the crystal.
  • Its solid form is an insulator because all valence electrons of carbon atoms are involved into the covalent bonds within the individual carbon molecules.

• Ionic Bonding and Electron Transfer

  • At the macroscopic scale, ionic compounds form lattices, are crystalline solids under normal conditions, and have high melting points.
  • Most of these solids are soluble in H2O and conduct electricity when dissolved.
  • Ionic bonds differ from covalent bonds.
  • However, in covalent bonds, the electrons are shared between the two atoms.
  • In this video, Paul Andersen explains how ionic solids form when cations and anions are attracted.

• Percent Ionic Character and Bond Angle

  • Chemical bonds are more varied than terminology might suggest; they exist on a spectrum between purely ionic and purely covalent bonds.
  • To answer this question, consider the data on the ionic solid LiF.
  • The electron-pair bond is clearly responsible for this situation; this provides the covalent bond's stability.
  • There is nothing wrong with using the term "ionic bond" to describe the interactions between the atoms in the very small class of "ionic solids" such as LiF and NaCl.
  • Does this make an ionic bond, a covalent bond, or something in between?

• Binary Hydrides

  • Hydrides can be components of discrete molecules, oligomers, polymers, ionic solids, chemisorbed monolayers, bulk metals (interstitial), and other materials.
  • Hydrides can be characterized as ionic, covalent, or interstitial hydrides based on their bonding types.
  • Covalent hydrides refer to hydrogen centers that react as hydrides, or those that are nucleophilic.
  • In these substances, the hydride bond, formally, is a covalent bond much like the bond that is made by a proton in a weak acid.
  • Transition metal hydrides also include compounds that can be classified as covalent hydrides.

• Chemical Bonding & Valence

  • Sodium chloride is an ionic compound, and the crystalline solid has the structure shown on the right.
  • A different attractive interaction between atoms, called covalent bonding, is involved here.
  • Covalent bonding occurs by a sharing of valence electrons, rather than an outright electron transfer.
  • Examples of covalent bonding shown below include hydrogen, fluorine, carbon dioxide and carbon tetrafluoride.
  • This is an example of a double covalent bond.

• Factors that Affect Reaction Rate

  • In a reaction between a solid and a liquid, the surface area of the solid will ultimately impact how fast the reaction occurs.
  • This is because the liquid and the solid can bump into each other only at the liquid-solid interface, which is on the surface of the solid.
  • The solid molecules trapped within the body of the solid cannot react.
  • Therefore, increasing the surface area of the solid will expose more solid molecules to the liquid, which allows for a faster reaction.
  • For example, a reaction between molecules with atoms that are bonded by strong covalent bonds will take place at a slower rate than would a reaction between molecules with atoms that are bonded by weak covalent bonds.

• Borates: Boron-Oxygen Compounds

  • Two experimental studies have proposed the existence of diamond-like and graphite-like B2O, as for boron nitride and carbon solids.
  • It is a white, glassy solid with the formula B2O3.
  • Boron suboxide (chemical formula B6O) is a solid compound containing six boron atoms and one oxygen atom.
  • Due to its short interatomic bond lengths and strongly covalent character, B6O displays a range of outstanding physical and chemical properties such as great hardness (close to that of rhenium diboride and boron nitride), low mass density, high thermal conductivity, high chemical inertness, and excellent wear resistance.