Hydrogen how many covalent bonds

An atom that shares one or more of its electrons will complete its outer shell. Covalent bonds are strong - a lot of energy is needed to break them. Substances with covalent bonds often form molecules with low melting and boiling points, such as hydrogen and water. The slideshow shows a covalent bond being formed between a hydrogen atom and a chlorine atom, to form hydrogen chloride. A hydrogen atom with one electron and a chlorine atom with 17 electrons.

The hydrogen atom has bonded with the chlorine atom, meaning there is now a shared pair of electrons. By each contributing one electron, they make the following molecule:. In this molecule, the hydrogen atom does not have nonbonding electrons, while the fluorine atom has six nonbonding electrons three lone electron pairs. The circles show how the valence electron shells are filled for both atoms.

Larger molecules are constructed in a similar fashion, with some atoms participating in more than one covalent bond. For example, water, with two hydrogen atoms and one oxygen atom, and methane CH 4 , with one carbon atom and four hydrogen atoms, can be represented as follows:.

Atoms typically form a characteristic number of covalent bonds in compounds. Figure 4. In molecules, there is a pattern to the number of covalent bonds that different atoms can form. Each block with a number indicates the number of covalent bonds formed by that atom in neutral compounds. Draw the Lewis diagram for the covalent bond in the Br 2 molecule. Draw the Lewis diagram for the covalent bond in the I 2 molecule.

Draw the Lewis diagram for the covalent bond in the HCl molecule. Draw the Lewis diagram for the covalent bond in the HI molecule.

What is the difference between a molecule and a formula unit? Why do hydrogen atoms not follow the octet rule when they form covalent bonds? Draw the Lewis diagram for the covalent bonding in H 2 S. How many bonding electrons and nonbonding electrons are in the molecule? Draw the Lewis diagram for the covalent bonding in NI 3. Draw the Lewis diagram for the covalent bonding in CF 4. Draw the Lewis diagram for the covalent bonding in PCl 3.

How many covalent bonds does a hydrogen atom typically form? How many covalent bonds does an oxygen atom typically form? Tellurium atoms make covalent bonds. How many covalent bonds would a tellurium atom make?

Predict the formula of a compound between tellurium and hydrogen. Tin atoms make covalent bonds. How many covalent bonds would a tin atom make? Polyatomic ions bond with other ions in the same way that elemental ions bond, with electrostatic forces caused by oppositely charged ions holding the ions together in an ionic compound bond. Charges must still be balanced. For example, in Fig. In Figure 2. P olyatomic ions can bond with monatomic ions or with other polyatomic ions to form compounds. In order to form neutral compounds, the total charges must be balanced.

A molecule or compound is made when two or more atoms form a chemical bond that links them together. As we have seen, there are two types of bonds: ionic bonds and covalent bonds. In an ionic bond, the atoms are bound together by the electrostatic forces in the attraction between ions of opposite charge.

Ionic bonds usually occur between metal and nonmetal ions. For example, sodium Na , a metal, and chloride Cl , a nonmetal, form an ionic bond to make NaCl.

In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals. For example, in water H 2 O each hydrogen H and oxygen O share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom.

In general, ionic bonds occur between elements that are far apart on the periodic table. Covalent bonds occur between elements that are close together on the periodic table. Ionic compounds tend to be brittle in their solid form and have very high melting temperatures.

Covalent compounds tend to be soft, and have relatively low melting and boiling points. Water, a liquid composed of covalently bonded molecules, can also be used as a test substance for other ionic and covalently compounds. Ionic compounds tend to dissolve in water e. Properties of ionic and covalent compounds are listed in Table 2. The properties listed in Table 2. Like other ionic compounds, sodium chloride Fig. Chlorine gas Fig. Ionic and covalent compounds also differ in what happens when they are placed in water, a common solvent.

For example, when a crystal of sodium chloride is put into water, it may seem as though the crystal simply disappears. Three things are actually happening. Ionic compounds like sodium chloride dissolve, dissociate, and diffuse.

Covalent compounds, like sugar and food coloring, can dissolve and diffuse, but they do not dissociate. Without stirring, the food coloring will mix into the water through only the movement of the water and food coloring molecules. As water evaporates, the salt solution becomes more and more concentrated.

Eventually, there is not enough water left to keep the sodium and chloride ions from interacting and joining together, so salt crystals form. This occurs naturally in places like salt evaporation ponds Fig. Salt crystals can also be formed by evaporating seawater in a shallow dish, as in the Recovering Salts from Seawater Activity. This document may be freely reproduced and distributed for non-profit educational purposes. Skip to main content. Search form Search.