So, all physical substances that have mass and take up space are known as matter. Try to remember it as: protons are positive, electrons are n e native, and neutrons are neutral (n o charge).
An example would be the element (aka atom) hydrogen (denoted by H). A molecule comprises groups of atoms that have chemically bonded together.
Well, the charge of an atom is the basis for ionic bonding. All electrons are organized into shells (also known as energy levels or orbitals).
This tendency of atoms to prefer having 8 electrons in their valence shell is known as the octet rule. Of these two, the atom will always choose the option that requires the least amount of energy.
Where the atom’s electronegativity falls on the scale is how the three bonding types (ionic, polar, and nonpolar) are classified. For example, a sodium atom (Na) has an electronegativity of 0.93 which is very weak.
It can often be confusing to remember the different terms used to describe atoms (and molecules) since they can be many things at once so let’s look at some examples to help us better understand ionic vs covalent. Ionic Example An example of ionic bonding would be the bond between a sodium atom and a chlorine atom (salt which is written NaCl).
Remember that ionic bonding occurs between two ions. Also, remember that ionic bonds are normally (but not always) formed between metallic and non-metallic atoms.
Polar Covalent Example An example of polar covalent bonding would be the bond between an oxygen atom and two hydrogen atoms (water which is written as H 2 0). The two hydrogen atoms are also neutral because they have an equal number of protons and electrons (both hydrogen atoms have 1 proton and 1 electron).
This gives oxygen a total of 10 electrons and 8 protons making it an ion. However, the hydrogen cannot fully give up their 1 electron, so they remain neutral.
Remember that both atoms would need to be ions to form an ionic bond. In this case, only oxygen is an ion (oxide), while the two hydrogen atoms are neutral.
Also, covalent bonds form between two nonmetals and both oxygen and hydrogen are nonmetallic. All three of the atoms (the oxygen ion and both hydrogen) are polar because they share their electrons unequally.
This means that the oxygen ion has a stronger pull (or attraction) on the electrons than the hydrogen do. Nonpolar Covalent Example An example of a nonpolar covalent bond would be the bond between two hydrogen atoms (hydrogen gas which is written as H 2).
The hydrogen atoms are both neutral since they have an equal number of protons and electrons (both hydrogen atoms have one proton and one electron). The easiest option for both hydrogen atoms is to share their one electron.
Since they are sharing their electrons (neither one has lost or gained), they are bonded covalently. Ionic bonding normally occurs between a metallic and a nonmetallic atom.
Both hydrogen atoms are nonpolar because they share their electrons equally. We can also use the Pauling scale to classify the hydrogen gas molecule.
When the electrons are not equally shared, a separation of electric charge occurs. Since both hydrogen atoms are neutral (equal electrons and protons) and the oxygen ion is negative (more electrons than protons) this also causes unequal distribution (polarity) in the water molecule.
The oxygen ion is stronger (it has more electrons), and also has a higher electronegativity. Therefore, it has a greater pull (or attraction) over the electrons in the hydrogen atoms.
So, the oxygen ion ends up having a partial negative charge, and the hydrogen atoms end up having a partial positive charge. Within covalent bonds, there are the two types: polar vs nonpolar.
This is due to polarity as well as electrostatic force (also called Coulomb’s force) which is attraction or repulsion due to electric charge. Electrostatic force is what holds ions (with opposing charges) together.
Remember, that the sharing of electrons is what holds covalent bonds together and not the attraction (or force) between opposing charges. To maximize their electrostatic force, most ionic compounds form large, lattice-shaped networks which are very strong and stable.
So, even though ionic bonds have a lot of polarity (therefore they should be weaker), because they have stronger formations (and they have more electrostatic force) they are typically stronger than covalent bonds. Dipole interaction also plays an important role in how molecules react with one another.
This interaction between dipoles is due to the negative (or slightly negative) charge on one molecule being attracted to the positive (or slightly positive) charge on another molecule and vice versa. Remember, that ionic bonding occurs between two ions.
We can see how these forces come into play regarding physical properties when we look at some of our previous examples. If we look at our ionic example (salt), we know that molecules that are formed by ionic bonding are stronger (have more electrostatic force) and harder to break (requires more energy to break) than those formed by covalent bonds.
Therefore, typically ionic compounds have a higher boiling point (and a higher melting point) than those formed by covalent bonds. Salt (which is ionic) has a boiling point of 2,675 o F and water (which is polar covalent) has a boiling point of 212 o F. This is because salt has a higher electrostatic force and a stronger dipole interaction (ion-ion interaction).
We can also see how polarity and dipole interaction affects a molecule’s physical properties even within the same bond category. Also, since water is a polar molecule, this means it also has dipoles (the oxygen ion has a partial negative charge, and the hydrogen atoms have partial positive charges).
Oil, on the other hand, is a nonpolar covalent molecule, so it does not have dipoles. Ionic vs covalent can initially be very confusing but try to remember that ion IC bonding occurs between ions (atoms or molecules with an unequal number of protons and electrons) and covalent bonding occurs when atoms have electrons in common (they share).
Ionic bonding mainly occurs with nonmetallic and metallic atoms bonding together, and the molecules have no fixed position (defined shape). Covalent bonding mainly occurs with nonmetallic atoms, and the molecules do have a fixed position (defined shape).
Covalent bonds can be further broken down into polar vs nonpolar. Polar bonds are when atoms share electrons unequally, and nonpolar bonds are when atoms share electrons equally.
This polarity creates dipoles in a molecule that result in positive (or partial positive) charges and negative (or partial negative charges). Electrostatic force, polarity, and dipole interactions all play a role in determining many of a molecule’s physical properties such as boiling point, melting point, and solubility.