I am asking this because I have a review question in my physics class which gives me a multiple-choice question. I have heard and seen elsewhere on the internet (such as wikipedia) that chemistry is the study of reactions and the properties of matter. That is usually a satisfactory answer, but for whatever reason this question makes me choose between reactions, properties, and matter. Now I find that the general definition I accepted contains basically all of those, as far as I can tell. While I don't necessarily need the answer, my curiosity has been aroused and I want to know why the question makes me choose between those answers.

The question is, what is the very basic idea behind chemistry? Would it be classified as the study of reactions, properties, or matter (and you can only select one)?

  • $\begingroup$ Is it possible that several answers are correct in that multiple-choice exam? $\endgroup$
    – tschoppi
    Jan 23 '14 at 6:18
  • $\begingroup$ Unfortunately, no (it's part of an online review exam and the questions use radio buttons, not checkboxes) $\endgroup$
    – person27
    Jan 23 '14 at 6:35
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    $\begingroup$ Chemistry is what chemists are doing. $\endgroup$
    – user26143
    Jan 23 '14 at 14:13
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    $\begingroup$ Personally, I think this question is rather ill-defined. I have yet to see a good answer to this question in general that is a single sentence long, much less one that can be answered by "It is the study of ______(single word)" $\endgroup$
    – chipbuster
    Jan 23 '14 at 19:59

While the answers so far are not wrong, I'd like to add a refinement. Chemistry is the study of matter at the level of electron interaction. The basic question in chemistry is about chemical bonding, and as far as we know this is a function of electron interaction. In contrast, radioactivity is also about matter, but is not at all about electron interaction and is not generally considered chemistry (it's considered a part of physics). Also, the chemistry of isotopes (i.e. differing neutron count) is not generally different across different isotopes. This is good, because we need solvents with are deuterium based ($\ce{D=^2H}$) as opposed to hydrogen based for NMR spectroscopy. If we go lower than electrons, we are into quantum mechanics, which is again physics. So electron interaction is a good level at which to characterize chemistry.

EDIT: I realize the original question was for a one-word answer. Frankly, that's not the greatest question, but it's generating answers that make it more interesting, and it's why I answered.

Let me give a counterexample to my own answer to show the difficulty: gases. We learn a lot about gases in chemistry which has nothing to do with chemical bonding; e.g. all the gas equations. I'd argue that most of this is not really chemistry, it's physics. Understanding how temperature, pressure, and volume interact dynamically is a very physical sort of study, not all that different from studying light, or magnetism, or force. So why do we study gas physics in chemistry? I suspect it's because we use gas physics a lot in chemistry! You need to understand the gas laws to do any real experimentation involving actual gas chemistry; i.e. how would you measure gas as a reactant or product without knowing the gas laws?

So to be clear, if you want one word, I agree with "matter". But I think if you want to get at what chemistry is about, it's not so simple.

  • $\begingroup$ Indeed I felt that the other answer lacked a mention of electron interactions. However, I think a refinement is needed; chemistry is the study of interactions concerning electrons bound to nuclei. This still isn't a perfect definition, but it narrows it down more. $\endgroup$ Jan 24 '14 at 1:52
  • $\begingroup$ "In contrast, radioactivity is also about matter, but is not at all about electron interaction and is not generally considered chemistry" -- Nuclear chemistry anyone? $\endgroup$ Jan 24 '14 at 12:30
  • $\begingroup$ @LordStryker: Well, the radioactivity observation (i.e. more physics than chemistry) came straight out of a good college level chemistry textbook. You can disagree, but as the answers are showing, this turns out to not be an easy question. I'm well aware of the old chestnut that chemistry is the study of anything you can drop on your foot (matter), but quantum mechanics has blurred some boundaries. In particular, I don't see a reason why we are likely to find a good one word answer. Matter is probably as close as we can get, and it's incomplete, in my view. $\endgroup$
    – user467
    Jan 24 '14 at 12:52
  • $\begingroup$ @trb456 "this turns out to not be an easy question" - You're overthinking it and the OP asked for one of the three options to be chosen. Besides, science overlaps in so many ways that you CAN'T draw clear boundaries between what is strictly say 'chemistry' or 'physics' or 'math' etc. Why would anyone want to anyway? It just seems silly. $\endgroup$ Jan 24 '14 at 13:51

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure, and properties. Chemistry is sometimes called "the central science" because it bridges physics with other natural sciences such as geology and biology.

  • $\begingroup$ Could you choose one? I'm starting to get the feeling that question I was asked really was nit-picking now. $\endgroup$
    – person27
    Jan 23 '14 at 6:35
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    $\begingroup$ I didn't notice anything discourteous about my behavior, so if I was rude then I apologize. In my statement above I said that my question wouldn't help anybody else, not that people were being unhelpful to me. I don't have sources to cite except for the review test my teacher gave me on elearning. $\endgroup$
    – person27
    Jan 23 '14 at 7:31
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    $\begingroup$ @Stopforgettingmyaccounts...The correct answer to the question is matter because this encompasses the other answers. But the reason is simply that in english things that happen to matter and properties are subsets of the broader category matter. And chemistry is a broad subject. $\endgroup$
    – matt_black
    Jan 23 '14 at 20:02
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    $\begingroup$ The thing about chemistry being the science of "matter" is that "matter" needs to be properly defined. If matter means particles with rest mass greater than zero, then approximately 85% of the matter in the Universe by weight is dark matter, for which chemistry has nothing to say. Excluding dark matter, by amount of particles ~99.999% of those with rest mass are neutrinos. I think calling chemistry the study of matter is a short but not very well self-contained explanation. $\endgroup$ Jan 24 '14 at 13:35
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    $\begingroup$ @NicolauSakerNeto Of course it isn't very self-contained. However one could debate for hours what exact concepts chemistry extends to. However nobody here really wants that. $\endgroup$ Jan 24 '14 at 13:47

This is a little review of the online definition I've found:

Oxford Dictionaries definition:

The branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances.

Cembridge Dictionaries definition:

(the part of science which studies) the basic characteristics of substances and the different ways in which they react or combine with other substances.

I like the Treccani, that here I've badly translate:

The science concerned with the properties, composition, identification, preparation and the different ways in which the natural and artificial substances react.

More mystic the Wikitionary definition:

The branch of natural science that deals with the composition and constitution of substances and the changes that they undergo as a consequence of alterations in the constitution of their molecules.

The point I find fundamental are that Chemistry concerned with matter and compounds and historically studied the methods to:

  • investigate the forces between them and their properties
  • separate and isolate them
  • analyze, identify and quantify them (and this is why I like Treccani definition because include analytical chemistry)
  • understand and predict the ways in which they combine and react
  • synthesize and produce new materials
  • find the way to produce the new material industrially

Chemistry is the study of chemical systems (i.e. matter).


The meaning of the word chemistry fluctuates with time.

According to Thomson, chemistry is derived from Egyptian word which meant "natural philosophy." This definition over time changed into the art of working with metals. About 300 AD it came to mean the art of making gold and silver. This art was passed from the Greeks to the Arabians. Supposedly around this time the Arabic 'al' prefix was attached to chemist to form the word alchemist.

Most alchemist who lived between about 900 AD and 1500 AD were in search of a substance, called the philosopher's stone, which converted metal into gold. Around this time alchemy also came to mean the "art of preparing a universal medicine."

In the 1600's alchemy fell into discredit and was the butt of many satires. With the passing of alchemy, chemistry was organized as a science. In the mid 1700's chemistry and mathematics became infused. At this point in time chemistry was a division of natural philosophy which was defined as "changes in natural bodies not accompanied by sensible motions."

The reality is the definition of the word chemistry has been changing as we better understand our world for thousands of years. Any definition is valid only for this point in history.

T Thomson - A system of chemistry (1810)


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