I'm a bit new in chemistry, so I need help with a couple of things. Although I don't mind complicated answers, please try to keep it around high school level, and not rocket science. Thanks!

  1. Can someone describe exactly what makes a compound a compound? Is it just the simple definition of "multiple elements combined" or can someone get a more specific?

  2. Sodium chloride is an ionic compound, but it's not made out of "molecules". So does that mean Sodium Chloride isn't an actual molecule (like $Na^+$ and $Cl^-$ are combined as separate ions but they can't be combined in a 1 to 1 fashion)

  3. Can someone explain to me exactly what the law of gaseous reaction is, (it doesn't show up on internet specifically, but it's a law by Gay-Lussac).

Thank you in advance!

  • 3
    $\begingroup$ This should probably be three different questions. $\endgroup$
    – Lighthart
    Jul 21, 2015 at 21:25
  • $\begingroup$ I didn't want to spam the forums, so I wanted to condense it, sorry if it's bad. $\endgroup$
    – phi2k
    Jul 21, 2015 at 21:27
  • $\begingroup$ Small quibble - this is not a forum $\endgroup$
    – user15489
    Jul 22, 2015 at 6:52
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    $\begingroup$ Don't worry; if you post them as three different questions they can be dealt with better and extensively. Also, it would really be more appreciable if you provide your thoughts and your confusion more elaborately. $\endgroup$
    – M.A.R.
    Jul 22, 2015 at 8:00
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    $\begingroup$ Agreeing with the earlier posts. Stack Exchange is not a forum. It is a question and answer site. You ask questions, we give answers. The community votes. Three questions means three times as many opportunities to earn rep (which is good!). For more information about how our site works, consider taking our tour or visiting our help center. $\endgroup$
    – Ben Norris
    Jul 23, 2015 at 1:47

1 Answer 1


A molecule is formed when two or more atoms join together chemically e.g. Na and Cl.

A compound is a molecule that contains at least two different elements e.g. Na and Cl.

All compounds are molecules but not all molecules are compounds e.g. H2 and O2 are molecules but are not compounds because bond is between two of the same elements.

Im not sure what you are asking in question 3. Gay-Lussacs Law is generally associated with the combining volumes principle. e.g. 1 volume of H2(g) + 1 volume of O2(g) = 2 volumes of H2O(g). However, you may want to consider the combined gas law, not just Gay-Lussac law. This combines Gat-Lussacs law with Boyles' and Charles' Law.

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    $\begingroup$ I hope this helped, but I assume this is easily accessible via Google (etc.). In future, I would recommend trying to find the answers yourself first and then ask what you are confused on. $\endgroup$
    – LiamH
    Jul 22, 2015 at 21:04

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