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I need help on this.

  1. Jun 22, 2006 #1
    thanks hootenanny:wink:

    im not sure if my teacher had set this question wrongly or not? because im finding it hard to answer.

    the question goes:
    TWO statement below are INCORRECT. which are these 2 statements?
    A.) the nucleus of an atom contains only neutrons and protons.

    B.)The mass number(nucleon number) of an atom = number of protons + number of neutrons.

    C.)The Nucleus of an atom contains 3 protons and 4 neutrons. Thus, this atom has 3 valence electrons.

    D.)It is possible for the mass number(nucleon number) and atomic number(proton number) of an atom to be equal.

    E.)It is never possible for the number of neutrons and the number of protons to be equal.

    can anybody help? :confused:
    i could only pick out 1 incorrect statement which is C.
    but the question require 2.. so i hope somebody could help. thanks lotsa.:smile:
  2. jcsd
  3. Jun 22, 2006 #2


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    I'm not sure how much depth you have gone into, this is probably from chemistry class no? But this statement is technically incorrect. Protons and neutrons themselves are composed of quarks; also, in the nucleus there are many virutal particles which mediate the fundemental forces (strong, weak, EM and gravity). However, it is unlikely that you have gone into this much depth in chemistry class, but as far as I can see all the others, except (c) as you point out are correct.:confused:
    Last edited: Jun 22, 2006
  4. Jun 22, 2006 #3
    i think the choice no E is also wrong in the 1st question.

    eg in magnisium the no of protons is equal to no of neutrons(12)
  5. Jun 22, 2006 #4


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    Yes, I forgot to comment on this in this post, however, on my previous post I did say that;
    So, the obvious choices here would be C and E. Apologies for the confusion.
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