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

Homework Help: Atom of argon charge

  1. Sep 25, 2006 #1
    A little help with electron work

    Hi, I'm new and I was wondering if anyone could help me with this

    An atom of argon

    37
    Ar
    18

    is ionised by the removal of 2 orbiting electons.
    In the ion there will be..

    a) ______ protons and ______ neutrons

    b) So what is the charge in C of this ion?

    __
    note, having tried this I got 18 protons and 18 neutrons but have no clue about b and I'm not sure if a is true.
    Thankyou if anyone can assist me, I'd be very greatful indeed.
     
    Last edited: Sep 25, 2006
  2. jcsd
  3. Sep 25, 2006 #2

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    18 + 18 = 36. But the number above the symbol is 37. So, 18 protons plus how many neutrons will give you 37 "nucleons"?

    No clue about b? How many electrons are missing? (2) . What the charge of each electron?
     
  4. Sep 25, 2006 #3
    19 neutrons? thanks.

    Also, for b would it be double the charge of an electron?
    2 x 1.6x10^-19?

    Also, can I ask what a constituent particle is?
    it says ask for one for this ion that has
    a zero charge per unit mass ration
    and the largest charge per unit mass ratio.
     
  5. Sep 25, 2006 #4

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    2 x "e" that's correct. You might need to specify that the net charge is positive, since the ion is missing electrons.

    As for the second part: talk about an obtuse way of stating the question. "Constituent particle" is referring to the three fundamental particles that make up atoms (electron protons and neutrons).

    The question asks: "Which particle has no net charge (regardless of it's mass), and which particle has least mass."
     
  6. Sep 26, 2006 #5
    thankyou very much for your help. :)

    I have another problem that is troubling me in this paper
    A

    239
    92 U

    nucleus may decay by emitting to beta- particles to form a plutonium nucleus.

    X
    Y P

    State what Xand Y represent and their values.

    Well I think that X would be the number of nucleons and Y the number of protons but I'm puzzled as to how I'd solve it.
     
  7. Sep 26, 2006 #6

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    Do you know what happens in "beta decay"? OK I'll tell you. A neutron "changes into" (the whole story is advanced and more complicated) a proton and ejects a high-speed electron (that's the beta particle). Does the X number change? HOw about the Y number?

    (By the way, what you call "X" should be called "A," and what you call "Y" shoulc be called "Z." The A number is the nucleons or mass number, the Z number is the protons or charge number.)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook