If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Predicting bond type (metals vs. nonmetals)

One way to predict the type of bond that forms between two elements is to consider whether each element is a metal or nonmetal. In general, covalent bonds form between nonmetals, ionic bonds form between metals and nonmetals, and metallic bonds form between metals. Created by Sal Khan.

Want to join the conversation?

  • piceratops ultimate style avatar for user Sayan Mondal
    if non metals are bad conductor of electricity the why graphite( an allotrophe of carbon) is a good conductor electricity??
    (3 votes)
    Default Khan Academy avatar avatar for user
    • aqualine sapling style avatar for user Projjal
      Yes, most Non-metals are bad conductors of electricity but there is an exception for Graphite because of its structure.
      Its structure - https://tirupatigraphite.co.uk/images/molecular-structure-flake-graphite.png
      If you notice, you will see that every Carbon atom is covalently bonded with others, using Only 3 of its valence electrons, while another electron remains free. Because of such free electrons of all the Carbon atoms in that allotrope, electricity flows easily through it using those delocalized (free) electrons.
      Even though generally, non-metals are bad conductors and metals are good, there always exist exceptions in nature. And we learn that with time and research :)
      Ask if anything is unclear.
      (11 votes)
  • blobby green style avatar for user Janerie Basaygan Aguirre
    is Ununoctium (118) a metal or nonmetal, a noble gasses or not?
    (3 votes)
    Default Khan Academy avatar avatar for user
    • leaf red style avatar for user Richard
      Firstly, element 118 is no longer named ununoctium and has not been named so since 2016. Ununoctium was a placeholder name for element 118 giving by the IUPAC in 1979 which was intended to be used until its discovery was confirmed since the people who discover an element gain the right to name it. In 2016 is was officially decided to name it Oganesson (which the chemical symbol of Og) after Russian physicist Yuri Oganessian whose team helped synthesize superheavy elements 107 through 118. It was given the "-on" suffix since it belongs to group 18 along with the noble gases who all have suffixes of "-on".

      So since so few atoms of Og have been created it's hard to say conclusively what it's properties are as of now. It's in the same group as the noble gases (which are nonmetals), but has been hinted that it may be solid under normal conditions and significantly reactive. Which would be a break from the trend of the group of unreactive gases at normal conditions. So it's unclear as of now what it is.

      Hope that helps.
      (9 votes)
  • blobby green style avatar for user sm2701
    Why can’t oxygen and hydrogen form an ionic bond with oxygen stealing two electrons from the hydrogens, making it two hydrogens with a plus 1 charge and one oxygen with a -2 charge? I know how they can form a covalent bond but why can’t they also form an ionic bond? If it’d rather form a covalent bond, could you “force” it to make an ionic bond but adding some energy or something?
    (2 votes)
    Default Khan Academy avatar avatar for user
    • leaf red style avatar for user Richard
      For an ionic bond to happen, the electronegativity difference between the two bonding atoms has to be large enough. A large electronegativity difference means that a very electronegative atom was bonded with a not so electronegative atom. The very electronegative atom in an ionic bond will attract electrons to itself to such a degree that it removes electrons from the other, less electronegative atom.

      Using the Pauling scale of electronegativity we need a difference greater than 2.0, x > 2.0. Hydrogen's electronegativity value is 2.20 while oxygen is 3.44, which result in a difference of 1.24 (3.44 - 2.20 = 1.24). This would place the hydrogen oxygen bond in the polar covalent range instead of the ionic range. So hydrogen and oxygen do not form an ionic bond simply because they do not have a large enough electronegativity difference. We can't do anything to change the polar covalent bond into an ionic bond because it's the identity of the elements which is determining the type of bond.

      Hope that helps.
      (6 votes)
  • piceratops seed style avatar for user Bentley, Jude
    What makes the noble gases "noble"?
    (2 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user Ashwani Kumar
    is there any kind of limitation in ionic bond formation?
    (2 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user vageesharupasinghe
    how to find the valency of non metals
    (1 vote)
    Default Khan Academy avatar avatar for user
  • stelly blue style avatar for user Kolibri
    apparently metalloids (like Germanium) act unusually in chemical bonds, How so? how would Ge bond with F (nonmetal) and how would it bond with sodium (metal) if they could bond?
    (1 vote)
    Default Khan Academy avatar avatar for user

Video transcript

- [Instructor] In a previous video, we introduced ourselves to the idea of bonds between atoms, and we talked about the types of bonds, ionic, covalent and metallic. In this video we're going to dig a little bit deeper and talk about the types of bonds that are likely to be formed between different elements. And to understand that, I'm going to introduce a broad classification of the elements, and in general, we're just going to think about things as metals and as nonmetals. So before I even point out on the periodic table of elements what are the metals and what are the nonmetals and maybe what are the ones that are in between, what are the properties of metals? Well, generally speaking, they conduct electricity. Conduct electricity. They tend to be malleable, which is just a fancy way of saying that you can bend them without breaking. And generally speaking, and there's exceptions to this, they are solid at room temperature. So I'll say solid at room temperature. Now what do you think the properties of nonmetals are going to be? Well generally speaking, they're going to be the opposite of this. Nonmetals, generally speaking, at room temperature are often not solid, they're often times gasses. They are not going to conduct electricity well. Now when you look at a periodic table of elements, how do you divide the metals from the nonmetals? Well that's what this little scratchy yellow line I'm drawing is trying to indicate. So everything above and to the right of this yellow line is a nonmetal and if you look at the color code from the folks who made this periodic table of elements, everything in this yellow color that we have here, so hydrogen and carbon and nitrogen and oxygen and fluorine, chlorine, I could keep going, these are all nonmetals. And it is the case that generally speaking at room temperature, they will be in a gas form and they will not conduct electricity well. These things in blue we've talked about in other videos, these are the noble gasses. So these are also nonmetals. The people who made this periodic table of elements put them in their own color 'cause then you could view them as a subclass of nonmetals and they tend to be very inert, they don't interact with other things. They don't tend to form any of these bonds. Now everything else, you can consider in some form to be a metal and the reason why this periodic table of elements has different colors is that there's subclassifications of the metals but generally speaking, all of these things that you see right over here below this scratchy yellow line have the properties, generally speaking, of conducting electricity, being malleable, being solid at room temperature. And these things that straddle this yellow line right over here, these things that are in this kind of bluish-green kind of color, these are sometimes viewed as metalloids because they have some properties of metals and some properties of nonmetals. But generally speaking, if you know whether the things reacting are metals or nonmetals, you can oftentimes predict what type of bond is going to form. So for example, if I have a bond between a metal, a metal and a nonmetal, and a nonmetal, what type of bond do you think is going to form? Well when you bond between a net metal and a nonmetal, and we saw an example of that in that first video on bonding, say a metal like sodium, and then a nonmetal like chlorine, we saw that that chlorine will swipe an electron, the sodium might lose one, then the chlorine atom becomes a chloride anion, and then the sodium atom becomes a sodium cation and then they become attracted to each other and then you form an ionic bond. So this tends to form ionic bonds. Now what if you were to have a nonmetal with a nonmetal? Nonmetal times two, so two nonmetals bind, bound, I'm having trouble saying it, two nonmetals bonding to each other. What do you think is going to happen? Well we saw as an example in that first video where we say well what happens if oxygen bonds to oxygen? Well we saw that was a covalent bond and that is generally the case when you have two nonmetals form bonds, it is covalent. And then last but not least, and this might be the most obvious one of them all, what do you think happens when you have two metals forming a bond? Well you can imagine that will be a metallic bond where they contribute electrons to this kind of sea of electrons and that's what makes them conduct electricity so well and malleable. So I'll leave you there. There are exceptions to everything I just talked about but generally speaking, these notions will serve you well, especially in an introductory chemistry class.