Ionic and Covalent Bonds

Cierrah Flaig and Nicole Womaski

What’s an Ionic Compound?

When one or more electrons are removed from a metal and transferred to a nonmetal resulting in attraction between positive and negative ions

Now that you are informed on what each bond is, you are ready to learn which elements are involved in each bond, the roles of the electrons, why the bonds form, the formation of the salt, different types of bonds such as- single, double, and triple; and some physical characteristics of each bond.

Nonmetals and Metals are the types of elements associated with ionic bonding. Since metals have very few electrons in their outer energy level, they lose them more willingly. In order to removed electrons you need to have ionization energy. Nonmetals have one or two valence electrons missing from their outer electron configuration therefore will not be as readily to lose electrons, resulting in higher electron negativity. Instead, they usually gain more electrons. When nonmetals gain electrons, this is called electron affinity.

Remember when we defined what an ionic bond was? We talked about how in the end positive and negative ions are attracted to each other. The question is, how did these positive and negative ions form? First off, you have to try and satisfy the octet rule for both positive and negative ions!

A cation, or also known as a positive ion, is formed by removing electrons from atoms. An anion, or negative ion, is formed by adding electrons to the atom. Since nonmetals and metals have the ability to gain and lose electrons that is why they are the only elements involved with ionic bonding.

Why do ionic bonds from and how does it happen?

Ionic bonds form due to an atom that doesn’t have enough electrons and then gives off electrons to an atom that is worse off When this type of bond is formed, lattice energy is released.

Like we said earlier, electron affinity is the energy needed to gain an electron but there is another type of energy that is very important when dealing with transferring electrons. Ionization energy is the energy that is needed to remove an electron. Adding and removing electrons isn’t the only step in forming an ionic bond. The other part is the formation of the salt.

Without salt formation ionic bonds would not occur. While forming salt, the process begins with energy input and ending with energy output. Way more energy is released at the end of the formation then the beginning. Sodium and chlorine both need energy added to them to convert them from a solid to a gas. Since sodium and chlorine are now gasses, more energy needs to remove an electron from each sodium atom.

At Room Temp.

-Sodium Chloride - is a solid-able to crush into powder- does not conduct electricity

As a powder

In Distilled Water and Burning

Sodium Chloride in distilled water:- conducts electricity- dissolves

Sodium Chloride Burning:- very high melting point

Dissolving

What are Covalent Bonds?

A covalent bond occurs when two atoms share valence electrons with each other.

Carbon compounds, or organic compounds, are often associated with Covalent Bonds. Hydrogen and Oxygen are also involved with these bonds.

Covalent bond are formed between two non-metals that have similar electro negativities. Neither of the two non-metals are strong enough to attract electrons from the other. So to get stabilized, they share their electrons from outer orbits.

Polar Covalent Bonds

These bonds are created when the shared electrons between atoms are not equally shared. When one atom has higher electro negativity than the atom that its sharing with, this occurs. The atom with the higher electro negativity will have a stronger pull. Then the shared electrons will be closer to the atom with the higher electro negativity, making it unequally shared. Also the atoms that are higher will take on the partial negative charge.

Non-Polar Covalent Bonds

When atoms share their electrons equally they are created. When two atoms have similar or the same electron affinity it occurs. The closer the values of their electron affinity, the stronger the attraction. This occurs in gas molecules, also known as diatomic elements.

Single Bond

When two electrons one pair of electrons are shared between two atoms. This is the most stable bond because it has a lower level of reactivity meaning in loosing electrons to atoms that want to steal electrons. Single bonds have a smaller density and are much weaker.

Double Bond

When two atoms share two pairs of electrons amongst each other. It is depicted by two horizontal lines between two atoms in a molecule. This type of bond is much stronger than a single bond but less stable.

Triple Bond

When three pairs of electrons are shared between two atoms in a molecule. It is the least stable out of the three general types of covalent bonds. Its very vulnerable to electron thieves.

With covalent bonds, there is electron negativity. Electron negativity is the ability to attract electrons towards itself. This type of energy is most useful for non metals but are used for other elements as well.

Characteristics

Covalent bonds have a specific shape and have low melting and boiling points. At room temperature these bonds can be liquid or gas. Covalent bonds solubility in water is high to low.

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