In this article, we discuss ionic bonding and covalent bonding, and compare ionic bonds vs covalent bonds. We’ll talk about what is an ionic bond, and what is a covalent bond. We’ll also give examples of both. Common table salt is an an example of common compound with ionic bonds. Ionic compounds are often solids, and form crystals.
Carbon dioxide, gas we breathe out of our lungs, is a compound with covalent bonds. But what is the difference between ionic vs covalent?
What is a covalent bond?
So what is a covalent bond? There are two main types of chemical bonds: covalent bonds and ionic bonds. The definition of a covalent bond, is a bond where there are electron between the atoms that are shared fairly equally. The more equally they are shared, the more covalent character the bond has.
Covalent bonds occur between two non-metals or a non-metal, and a metalloid. There are two types of covalent bonding: polar and non-polar. Bonds between non-metals or a non-metal and a metalloid do not have large electronegativity differences.
Here is a simple explanation of a covalent bond. A covalent bond is a chemical bond that forms when two atoms share one or more pairs of electrons. This happens because the atoms are trying to fill their outermost energy level, or valence shell, with a full complement of electrons. When the atoms share electrons in this way, they become more stable and less likely to react with other substances. This is why covalent bonds are often found in molecules, which are groups of atoms held together by covalent bonds.
To be specific, the electronegativity difference between atoms in covalent bonds does not exceed 1.7. As a result of the similar electronegativity between atoms, the atoms share electrons. For example, the valence electrons in oxygen complete hydrogen’s outer electron shell. Likewise, the valence electron in hydrogen complete oxygen’s outermost electron shell. There is a funny image of covalent bonds here.
Definition of Ionic
The definition of the word “ionic”, is something that is related to, or involves ions – which are charged atoms or molecules. There are ionic bonds, ionic compounds, ionization – all of these concepts involve ions.
What is an ionic bond?
So what is an ionic bond? The definition of ionic bond, is a bond between atoms where electrons are (mostly) transferred from one atom to another. We say mostly, because there is always some sharing of electrons between atoms, but in Ionic bonds, the sharing is very unequal. The less equal the sharing of the electrons, the more ionic character the bond has.
Ionic bonds occur between a metal and a non-metal. Unlike covalent bonds, ionic bonds transfer their valence electrons between atoms. In ionic bonding, the electronegativity difference between non-metals and metals exceeds 1.7. The metal atom transfers its electrons to the non-metal atom. Therefore, the metal atom becomes a positively charged cation and the non-metal atom becomes a negatively charged anion. Consequently, ionic bonds create two charged ions, the metal always donates its electron, and the non-metal always accepts the electron. An example of an ionic bond is the bond in sodium chloride, which is salt. Sodium’s valence electron is transferred to the outer electron shell of chloride.
Molecules with ionic bonds form ionic compounds. Molecules with covalent bonds form covalent compounds. Covalent compounds often melt at lower temperatures, because their covalent bonds are easier to break. We hope you understand ionic vs covalent bonds and compounds a little better now.
Is NaCl Ionic or Covalent?
NaCl, sodium chloride or table salt, is the “classic” example of an ionic compound. Sodium is a metal, and chlorine is a non-metal. It has ionic bonds, has a crystalline structure. In solution, it separates into ions in solution.
Properties of Ionic Compounds
Differences between Compounds with Covalent and Ionic Bonds
The definition of an ionic compound, is a chemical compound composed of ions held together by electrostatic forces – basically held together by ionic bonds. They are formed by neatly packed ions of opposite charge. The compound is neutral, but it consists of positively and negatively charged cations and anions. Let’s look at some differences between ionic and covalent bonds and compounds.
- Ionic bonds tend to transfer electrons, covalent bonds share them more easily
- Ionic compounds tend to have higher melting and boiling points, covalent compounds have lower melting & boiling points
- Ionic compounds tend to have more polar molecules, covalent compounds less so
- Organic compounds tend to have covalent bonds
- Ionic compounds are usually between a metal and a non-metal. Non-metal with a non-metal compounds are covalent.
- Ionic compounds have ions in solution or in the molten state and conduct electricity
- Ionic bonds are much stronger than covalent bonds
- Ionic compounds tend to be a solid with a definite shape at room temperature, covalent compounds are usually gases, liquids or soft solids
- Ionic compounds often do not dissolve in organic solvents, while covalent compounds often do
We hope that gives you a better sense of ionic vs covalent.
Examples of Compounds with Ionic Bonds
Here are some ionic bond examples:
- Sodium chloride, NaCl
- Magnesium sulfate, MgSO4
- Cesium fluoride, CeF
- Strontium hydroxide, Sr(OH)2
- Potassium Cyanide, KCN
Examples of Compounds with Covalent Bonds
Here are some covalent bond examples:
- Water, H2O
- Methane, CH4
- Ammonia, NH3
- Tin (IV) iodide, SnI4
- Titanium (IV) chloride, TiCl4
Learn more on our Interactive Periodic Table
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Ionic vs Covalent – Further Reading
Naming Covalent Compounds
Naming Ionic Compounds
Polar vs Non-Polar Bonds