Ionic Bonding - Online Tutor, Practice Problems & Exam Prep

Ionic bonding involves the electrical attraction between oppositely charged ions, specifically cations and anions. Cations are positively charged ions formed by the loss of electrons, while anions are negatively charged ions created by the gain of electrons. This transfer of electrons fills the valence shells of both atoms, resulting in stable ionic compounds like sodium chloride (NaCl), commonly known as table salt. Understanding ionic bonds is crucial for grasping the fundamentals of chemical interactions and molecular formation.

Ionic Bonding

In this video, we're going to begin our lesson on ionic bonding. But before we can talk about ionic bonding, we first need to be able to understand what ions are and we need to be able to distinguish between anions and cations. And so ions are really just a general term that refers to atoms or molecules with a net electrical charge. Now the charge on an ion can either be a negative or a positive charge due to either the gain or the loss of negatively charged electrons. And so really this is what leads to the 2 types of ions which are once again anions and cations. And so anions, as their name implies with so many n's in their name are going to be negatively charged ions and these negatively charged anions are going to result from the gain of a negatively charged electron. And so, of course, if an atom gains a negatively charged electron then it can become an anion, a negatively charged ion. Now on the other hand, cations, as their name implies with the t here, are going to be positively charged. And so you can think the t is for the plus sign that means positively charged. So cations are positively charged ions that result from, of course, the loss of a negatively charged electron and so if an atom gives up something, a negatively charged electron then itself, it's going to become more positive, it's going to become more positive itself. And so if we take a look at our example image down below we can further distinguish between anions and cations.

So notice here in the center of our image what we're showing you is a single neutral hydrogen atom, and it is neutral because hydrogen atoms are characterized by having just one proton in their nucleus, and notice that it also has one electron here in this middle image, and so because it has one electron and one proton in its nucleus those two charges cancel each other out and what we get is a neutral hydrogen atom right here in the middle. Now if this neutral hydrogen atom were to gain a negatively charged electron like this one right here so that it now has 2 electrons instead of just 1 like it did before, then it's going to have one more electron than proton and that's going to give it an overall net negative charge like what we see here. And so this is what's going to make it an anion. Once again, you can think all of these ends here, the 2 ends in anion, suggest that it is negatively charged. Now on the other hand if we were to take this neutral hydrogen atom here in the center and this time we were to lose the electron, if there was a loss of the electron, and that electron were transferred to something else, then all we would have is a hydrogen atom with just a single proton in the nucleus and it would not have any electrons and so there would be a positive charge on this hydrogen atom. And so this is what makes it a cation and so you can think that, once again the t here in cation is for the plus sign and positive charge. And so really that's the biggest difference here between anions and cations. Anions are negatively charged whereas cations are positively charged. And if we're just saying the term ion then it could either be an anion or a cation. So we would have to further distinguish the ion to determine what it is. But for now this here concludes our introduction to ions, anions versus cations, and we'll be able to talk about the ionic bonding as we move forward. So I'll see you all in our next video.

When atoms gain or lose electrons, they become negatively or positively charged. They are known as:

• A. Molecules
• B. Isotopes.
• C. Ions.
• D. Radioactive.
• E. Unstable atoms.

Which of the following statements is true of ALL atoms that are anions?

• A. The atom has more electrons than protons.
• B. The atom has more protons than electrons.
• C. The atom has fewer protons than a neutral atom of the same element.

If oxygen has 9 electrons it will be a ______________________:

• A. Negatively charged cation.
• B. Negatively charged anion.
• C. Positively charged cation
• D. Positively charged anion

Ionic Bonds

So now that we've talked about ions, in this video we're going to talk about ionic bonds. And so ionic bonds are pretty much exactly what they sound like, they are bonds that form between ions. More specifically, we can define ionic bonds as electrical attractions between oppositely charged ions, between cations and anions. Now notice that ionic bonds do not have the word covalent in it. And recall from our previous lesson videos, the word covalent means sharing of electrons. But because ionic bonds do not have covalent, ionic bonds have no sharing of electrons. Instead, ionic bonds are characterized by a complete transfer of electrons. Now, this complete transfer of electrons can fill the valence shells of both atoms involved in the transfer, and because electrons are negatively charged, by transferring these negatively charged electrons it can create new charges and therefore create ions. And then those ions that are created can form an ionic bond. So, let's take a look at our example down below at the formation of the ionic bond in Sodium Chloride or NaCl. And so notice over here on the left-hand side, we're showing you a sodium atom and a chloride atom over here.

Now Chloride is much more electronegative than sodium, and what that means is that Chloride pulls on electrons a lot harder than sodium does. In fact, the discrepancy in electronegativity between these two atoms is so large that they don't even share electrons at all. Instead, chlorine is so much more electronegative than sodium that it's going to steal this electron and it's going to be completely transferred from the sodium to the chloride atom. What you'll notice is that the sodium has only one electron in its valence shell, and notice that the valence shell is the one that is highlighted here in pink it's the one that's furthest away from the nucleus. Once again it only has one electron in its shell, so if it loses this electron then its valence shell, it's gonna become this one and it will be full. And notice that over here the Chloride atom is missing just one electron in order to have a full valence shell. And so it's actually in the interest of both atoms for them to, undergo this transfer of electrons so that they both end up with these, they both can fill their valence shells. And so here what we're showing you is the electron transfer, from sodium to chloride. And so ultimately, what that means is the sodium atom, once again, it's going to have a new valence shell that is full. It gains a full octet. And the chloride is going to also have a full octet after the transfer.

Now another thing to note is that the sodium atom becomes a sodium ion, when the transfer is over. It gains a charge, and the chloride atom becomes a chloride ion once again because it also gains a charge. Because the chloride is gaining a negatively charged electron it's going to gain a negative charge. And so here in this little dotted box we can put a negative charge to remind us that the chloride ion is gonna have a negative charge. And of course, this sodium ion which is giving up a negatively charged electron is going to become more positive in the process, so it gains a positive charge. And so there is a natural attraction between positively charged cations and negatively charged anions, and so this interaction that we see right here forming between these two ions due to this attraction is what we call the ionic bond. And so what you can see is that, after the transfer of electrons that, we have completely filled valence shells and we have created these charges, these positive and negative charges just as we indicated up above. We filled the valence shells of both atoms and we create charges. And then also notice that down below, when you have the sodium ion and the chloride ion and they are forming, this ionic bond between the two ions, together the sodium and the chloride ions form a sodium chloride molecule and so it can still be a molecule by forming ionic bonds. And so, one thing to also note is that the sodium chloride molecule that you see right here is really what makes up your regular everyday table salt that you might have in your kitchen right now. And so, that's something important to also keep in mind. And so this here concludes our introduction to ionic bonds and we'll be able to get some practice applying these concepts that we've learned in our next few videos. So I'll see you guys there.

An ionic bond is a bond in which:

• A. Atoms share electrons
• B. Atoms share a proton.
• C. Atoms of opposite charges attract each other

Cations and anions would be most frequently associated with which of the following:

• A. Polar covalent bonds.
• B. Van der waals forces
• C. Ionic bonds
• D. Nonpolar covalent bonds.
• E. More than one of the above is correct

When are atoms most stable?

• A. When they have the fewest possible valence electrons
• B. When they have the maximum number of unpaired electrons.
• C. When the valence shell is completely full of electrons
• D. None of the above.

Which of the following neutral atoms would be most likely to lose an electron and become a cation of +1?

• A. A.
• B. B.
• C. C.
• D. D.

Here’s what students ask on this topic:

What is the difference between anions and cations?

Anions and cations are both types of ions, which are atoms or molecules with a net electrical charge. The key difference lies in their charges: anions are negatively charged ions formed by the gain of electrons, while cations are positively charged ions created by the loss of electrons. For example, when a neutral hydrogen atom gains an electron, it becomes a negatively charged anion (H⁻). Conversely, if it loses an electron, it becomes a positively charged cation (H⁺). Understanding this distinction is crucial for grasping ionic bonding, where these oppositely charged ions attract each other to form stable compounds.

How do ionic bonds form between atoms?

Ionic bonds form through the complete transfer of electrons from one atom to another, resulting in the creation of oppositely charged ions. For instance, in the formation of sodium chloride (NaCl), a sodium atom (Na) transfers its single valence electron to a chlorine atom (Cl). This transfer results in a positively charged sodium ion (Na⁺) and a negatively charged chloride ion (Cl⁻). The electrostatic attraction between these oppositely charged ions forms the ionic bond, leading to a stable ionic compound with filled valence shells for both atoms.

What is the role of electronegativity in ionic bonding?

Electronegativity plays a crucial role in ionic bonding by determining the tendency of an atom to attract electrons. In an ionic bond, one atom is significantly more electronegative than the other, leading to the complete transfer of electrons. For example, in sodium chloride (NaCl), chlorine is much more electronegative than sodium. This large difference in electronegativity causes chlorine to attract and gain an electron from sodium, resulting in the formation of a negatively charged chloride ion (Cl⁻) and a positively charged sodium ion (Na⁺). The electrostatic attraction between these ions forms the ionic bond.

Why is sodium chloride (NaCl) considered an ionic compound?

Sodium chloride (NaCl) is considered an ionic compound because it is formed through the ionic bonding of sodium (Na) and chlorine (Cl) atoms. In this process, sodium transfers its single valence electron to chlorine, resulting in the formation of a positively charged sodium ion (Na⁺) and a negatively charged chloride ion (Cl⁻). The electrostatic attraction between these oppositely charged ions creates a stable ionic bond, leading to the formation of NaCl. This complete transfer of electrons and the resulting ionic attraction are characteristic features of ionic compounds.

How does the transfer of electrons lead to the formation of ions?

The transfer of electrons between atoms leads to the formation of ions by altering the balance of protons and electrons in each atom. When an atom loses one or more electrons, it becomes a positively charged ion, or cation, because it has more protons than electrons. Conversely, when an atom gains one or more electrons, it becomes a negatively charged ion, or anion, because it has more electrons than protons. This transfer of electrons results in the creation of ions with opposite charges, which can then attract each other to form ionic bonds.