Why covalent bonds stronger than ionic

Negative ions are formed by gaining electrons. Atoms can lose and donate electrons in order to become more stable. When an element donates an electron from its outer shell, as in the sodium atom example above, a positive ion is formed Figure 2. The element accepting the electron is now negatively charged. Because positive and negative charges attract, these ions stay together and form an ionic bond , or a bond between ions.

The elements bond together with the electron from one element staying predominantly with the other element.

When Na and Cl combine to produce NaCl, an electron from a sodium atom goes to stay with the other seven electrons in the chlorine atom, forming a positively charged sodium ion and a negatively charged chlorine ion.

The sodium and chloride ions attract each other. Ionic and covalent bonds are strong bonds that require considerable energy to break. However, not all bonds between elements are ionic or covalent bonds. Weaker bonds can also form. These are attractions that occur between positive and negative charges that do not require much energy to break.

Two weak bonds that occur frequently are hydrogen bonds and van der Waals interactions. These bonds give rise to the unique properties of water and the unique structures of DNA and proteins.

When polar covalent bonds containing a hydrogen atom form, the hydrogen atom in that bond has a slightly positive charge. This is because the shared electron is pulled more strongly toward the other element and away from the hydrogen nucleus. This interaction is called a hydrogen bond. This type of bond is common; for example, the liquid nature of water is caused by the hydrogen bonds between water molecules Figure 4. This results in a positively charged ion cation and negatively charged ion anion.

The bond between these two ions is called an ionic bond. A covalent bond is formed between two non-metals that have similar electronegativities. Ionic or covalent? I've gotten conflicted answers when I googled this question online.

Re: Ionic vs Covalent Post by Harry Zhang 1B » Sat Sep 28, am Ionic bond is generally stronger because the ion-ion force that exists in ionic bonding is the strongest. In covalent bonds, electrons are shared, which doesn't generate a force as strong as that in ionic bonding.

This can also be explained when we compare the boiling points of ionic compounds and covalent compounds. Ionic compounds' boiling points are generally higher than covalent compounds' because it takes more energy to break the bonds in between ionic compounds. Re: Ionic vs Covalent Post by lasarro » Sat Sep 28, am Ionic bonds are usually stronger than covalent bonds. A defining characteristic of ionic bonds is that an electron from one atom is "taken" by another atom, whereas in covalent bonds, the electron is shared between the two atoms.

Re: Ionic vs Covalent Post by Ronak Naik » Sun Sep 29, am Ionic Bonds are stronger than covalent bonds because the electronegativity difference between the two elements is much greater than that of two elements in a covalent bond.

Covalent bonds allow the electrons to be shared between the two elements and will often favor one element over the other depending on polarity. Re: Ionic vs Covalent Post by Ally Huang- 1F » Tue Oct 01, pm Ionic bonds are usually stronger than covalent bonds because there is an attraction between oppositely charged ions. But, when molecules with ionic bonds are dissolved in water the ionic bonds become much weaker in comparison to covalent bonds after molecules with covalent bonds have been dissolved in water.

This could possibly be the reason you are finding different answers. Re: Ionic vs Covalent Post by Mellanie Gamero 4D » Tue Oct 01, pm Ionic bonds are stronger than covalent bonds due to the fact that they involve the transfer of electrons rather than an equal sharing of electrons, which occurs within covalent bonds, and usually, more energy is required to dissociate ionic bonds. The bond energy is the difference between the energy minimum which occurs at the bond distance and the energy of the two separated atoms.

This is the quantity of energy released when the bond is formed. Conversely, the same amount of energy is required to break the bond. For the H 2 molecule shown in Figure 5.

This may seem like a small number. However, as we will learn in more detail later, bond energies are often discussed on a per-mole basis. For example, it requires 7. A comparison of some bond lengths and energies is shown in Figure 5.

We can find many of these bonds in a variety of molecules, and this table provides average values. For example, breaking the first C—H bond in CH 4 requires As seen in Table 9.

We can use bond energies to calculate approximate enthalpy changes for reactions where enthalpies of formation are not available. Calculations of this type will also tell us whether a reaction is exothermic or endothermic.

This can be expressed mathematically in the following way:. The bond energy is obtained from a table like Table 9. Thus, in calculating enthalpies in this manner, it is important that we consider the bonding in all reactants and products. Because D values are typically averages for one type of bond in many different molecules, this calculation provides a rough estimate, not an exact value, for the enthalpy of reaction.

Because the bonds in the products are stronger than those in the reactants, the reaction releases more energy than it consumes:. This excess energy is released as heat, so the reaction is exothermic. Twice that value is — We can express this as follows:. Using the bond energy values in Table 9.