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Really basic netron/ electron stuff

  1. Feb 7, 2005 #1
    Write the symbol for these:

    a) 3 protons, 4 neutrons & 3 electrons...is it Lithium?
    b) 20 protons, mass number 40 and 18 electrons....is it Argon or oxygen??
    c) 10 electrons, net charge of 2- ....I have no clue
    d) 6 protons, 8 electrons, no charge...???
     
  2. jcsd
  3. Feb 7, 2005 #2

    dextercioby

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    Compute Z (atomic number) which identifies the element in the Periodic System and then A will tell u which isotope is ...

    Remember that the nomber of PROTONS specifies the chemical element... :wink:

    Daniel.
     
  4. Feb 7, 2005 #3

    chroot

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    The chemical properties of an atom are only determined by its atomic number, which is the number of protons in the nucleus. The number of neutrons affects the mass of the atom, but that doesn't directly affect its chemistry. The number of electrons is variable; atoms can lose electrons, or gain additional electrons. This affects the atom's charge, but does not change its chemical nature.

    a) The atom with 3 protons (forget the rest of the numbers) is always called Lithium, abbreviated Li. By convention, the mass of the atom is written as a subscript. The mass of this atom is 3 protons + 4 neutrons = 7 total nucleons. The mass of the electrons is very small and usually ignored.

    The atom with 20 protons (forget the rest of the numbers) is always called Calcium. (Look on your periodic table for atomic number 20.) You already know where the mass is written -- as a subscript. The charge is conventionally written as a superscript. In this case, there are 20 protons and only 18 electrons, so there are two units of "extra" positive charge. Write +2 as a superscript.

    c) Electrons are negatively charged and protons are positively charged. If you have one electron and one proton, there is no total charge -- the charges cancel. If an atom has 10 electrons, and an overall charge of -2, how many protons must it have?

    d) An atom with 6 protons is always called......? (Look up atomic number 6 on your periodic table.)

    - Warren
     
  5. Feb 7, 2005 #4
    Umm..so is this right?

    A) lithium
    b)Calcium
    c) ???
    d)carbon

    Are these right?

    *edit* i did not see the last post
     
  6. Feb 7, 2005 #5
    c) 8 protons..Oxygen?
     
  7. Feb 7, 2005 #6

    chroot

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    Roxy:

    You got it. Your teacher might be expecting you to not only name the elements, but to also write their symbols, complete with mass and charge. Do you have that figured out?

    - Warren
     
  8. Feb 7, 2005 #7
    yup, thank you :biggrin:
     
  9. Feb 7, 2005 #8

    dextercioby

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    That doesn't make sense...At this elementary level,the charges can come only from electrons & protons,so the total/net charge is "-2"... :wink:

    Daniel.
     
  10. Feb 7, 2005 #9

    Gokul43201

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    (d) is incorrect.
     
  11. Feb 8, 2005 #10
    This is right.
    This is not just an element. You said in a post before this you knew what you needed to do. What is that???
    It is oxygen but not just an element. Again, what is it???
    Nope and the original question suggests you would have no charge when there is a net charge of -2 (because there are 2 more electrons than protons). You might want to check the original question you got.

    The Bob (2004 ©)
     
  12. Feb 8, 2005 #11

    Gokul43201

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    Just to clarify, I meant "question (d) is incorrect".
     
  13. Feb 9, 2005 #12
    Yeap. I know. :smile:

    The Bob (2004 ©)
     
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