Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is it the protons or electrons that are responsible for an element's propert

  1. Nov 26, 2007 #1
    [SOLVED] Is it the protons or electrons that are responsible for an element's propert

    On a chemistry test I took, there was a question that asked "What subatomic particle is responsible for an element's physical and chemical properties"?
    I picked the "proton" as the answer choice, but the teacher's answer is "electron"

    I do not see why her answer is correct, not saying that I'm right. I understand that the electron, valence electrons respectively, are responsible for chemical reactivity. But what about physical? Since the number of protons also determine the number of electrons, the protons should be considered when it comes to elements physical and chemical properties. Physical, besides appearance, would be like boiling point and melting point and how can those properties be based on the number of electrons? the electrons are only responsible for chemical reactivity, right? If you know any sources, please cite them...
    Thanks
     
    Last edited: Nov 26, 2007
  2. jcsd
  3. Nov 27, 2007 #2

    HT3

    User Avatar

    electrons are responsible for bonding.
    therefore, boiling point, melting point, etc. are determined by the electron.
     
  4. Nov 27, 2007 #3
    Chemistry, really is all about the study of the outer electrons of an atom.
    The proton merely is a signature for an element. i.e it determines number of electrons in an electrically neutral atom
    Obviously if it is a huge element with lots of nucleons, then the physical properties will be inherently different (although the electrons still play a significant role), but the electrons are responsible for the chemical properties.
     
  5. Nov 27, 2007 #4
    That is a common question and the common answer is "electron"; but, actually, it's not a deep one. If you want to make your teacher feel uncomfortable, ask him/her: "So, if I remove a proton from an hydrogen's atom, I still have an atom with the same physical and chemical properties?" :wink:
     
    Last edited: Nov 27, 2007
  6. Nov 27, 2007 #5

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    This is a terrible question. There ought to be a good way to prevent this horror from being inflicted upon more students.
     
  7. Nov 28, 2007 #6
    No, does it even exist, actually?
    if it only has 1 neutron in the nucleus, then there will be no electronic attraction to the electrons, then either the ionization energy of that is VERY low, or even non existent, or is probably is somewhere else right now.

    If you remove a proton from say, Calcium, then it SHOULD change some properties. Since there is less electronic attraction to the electrons, so...
     
  8. Nov 28, 2007 #7

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The H-atom has no neutrons.

    If you pull a proton out of Calcium, you get K- (the number of neutrons matches). The latter is super reactive and will reduce anything within a mile of it.
     
  9. Nov 29, 2007 #8
    I guess that when they say "properties", it means a specific element. Since changing the number of protons (typically) changes the element, that doesn't satisfy the question.

    It still is quite a terrible question, though.
     
  10. Nov 30, 2007 #9
    Yes, it's terrible the same because the physical and chemical properties of an atom are given by the atom as a whole: the electrons's orbitals are not created by electrons only, but from the interaction nucleus-electrons.
     
  11. Dec 4, 2007 #10
    I did not know that. So in the molecule H2 there is no neutrons present, only 2 protons and 2 electrons?
     
  12. Dec 5, 2007 #11
    In a Pure Hydrogen Sample, MOST of the hydrogen will have no neutrons.
    Then there are isotopes.
    Deuterium and Tritium are isotopes, and they increase 1 and 2 neutrons respectively.
     
  13. Dec 5, 2007 #12
    Yes; is it surprising for you?
    Certainly, as Invictious said, in a normal (that is, non prepared) sample of hydrogen, there are all the three isotopes: H2, D2, T2, but H2 is the greater percent: 99.985%; D2 is 0.015% and T2 only traces. See:
    http://en.wikipedia.org/wiki/Hydrogen
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?