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Is an ionic compound the same as a molecule?

  1. Jul 10, 2013 #1
    A little clarification on the two....

    Would you agree with the text of the following two screenshots? (I highlighted the relevant parts in red)

    Most important is, screenshot 1 so please address it first:


    But also curious is, screenshot 2:


    Are these accurate?

    Would something like table salt rightfully be considered a molecule?

    I always thought ionic compounds were their own thing. But it seems to imply otherwise.

    Please explain.
  2. jcsd
  3. Jul 11, 2013 #2


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    Table salt is composed of molecules. A salt molecule is composed of one sodium (Na) atom and one chlorine (Cl) atom. Hence, the formula for table salt is: NaCl

    Ionic compounds are classified as such because of nature of the bonding of the individual atoms which compose the compound. Table salt is an ionic compound because sodium has a single electron in its outermost orbital, while chlorine has a full set less one of electrons in its outermost orbital. When chlorine and sodium react, the outermost electron from the sodium atom is easily captured by a nearby chlorine atom, which capture produces two ions: Na+ and Cl-. The oppositely charged ions are attracted to one another forming a salt compound. When salt is dissolved in water, these ions can separate and freely intermingle with one another.

    For more reading on ionic compounds: http://misterguch.brinkster.net/ionic.html

    Compounds which are covalently bonded are fundamentally different from ionic compounds. Because the constituent atoms in a covalent compound each are lacking more than one electron to fill their outermost orbitals, when these atoms react, they tend to share one another's outer electrons, temporarily filling the missing slots in the outermost orbitals.


    Ionic and covalent compounds differ in other physical and electrical characteristics. Ionic compounds dissolve easily in water and can conduct an electric current. Covalent compounds are generally insoluble in water and do not easily conduct an electric current.
  4. Jul 11, 2013 #3


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    Please don't abuse formatting, no need to post in bold.

    The first screenshot is plainly wrong, the second is most likely a lousy wording.
  5. Jul 11, 2013 #4
    I wasn't trying to abuse the formatting I just wanted it to stand out from the text in the screenshots (especially the first) so it would be more easily distinguishable, appear more organized, and easier to read. I think that is the purpose of using bold formatting; to draw attention to specific areas. The decision to bold the text was made after having previewed the post and seeing the text unbolded and considering how it appeared. The easier thing to do would be to make it bold so it would stand out and more easily distinguish where the screenshots end and where the text begins. It was just an aesthetic consideration. Knitpicking on that seems somewhat anal retentive. Also I would think some people would appreciate the contrast that bold text provides, especially those with visual impairment, or tiny screens. I have neither but I still prefer bold as it is easier on the eyes, but I have never even thought of it as potentially offensive or troublesome although that certainly is curious. There should be a way to disable bold text in about:config if that is truly an issue.

    Anyways, moving on from the bold text.... Can you elaborate on why the first is clearly wrong? I am not retarded I am just trying to gather as much reasons for this as possible since I was referred to the second site after having questioned the accuracy of the first along with a brief explanation relating to charges.

    I could not find any websites to cite, that specifically states anything as blatant as "an ionic compound is not a molecule" or vice versa, so the more detailed explanations - the better.
  6. Jul 11, 2013 #5


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  7. Jul 11, 2013 #6
    No it isn't. Table salt is composed of sodium and chlorine ions bound in a crystal lattice that looks something like this.

    Such a structure only exists in gaseous form - have you ever seen gaseous salt?

    In solid table salt each sodium ion is surrounded by six chlorine ions, and each chlorine ion is surrounded by six sodium ions, there is no 'pairing' into molecules.

    When table salt is dissolved in water the sodium and chlorine ions dissociate from each other completely and bond separately with water molecules.

    The formula for table salt is NaCl because it is a compound containing equal numbers of sodium and chlorine ions.

    Many atoms forming covalent compounds only lack one electron in their outermost orbital, the most obvious being Hydrogen. Many elements lacking more than one electron easily form ionic compounds, notably Oxygen.
    Last edited: Jul 11, 2013
  8. Jul 11, 2013 #7


    You were right, they are wrong.

    The internet is full of rubbish, get over it. For basic science the (obviously UK focused) BBC Bitesize is not perfect, but better than most.
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