Chemistry Clarity · chemistryclarity.com

Inside the Atom: Flashcards

Revise subatomic particles, atomic and mass numbers, ions and isotopes.

11 cardsBeginner

11 cards

  1. Question
    What are the charges of the proton, neutron and electron?
    Answer

    Proton +1, neutron 0, electron −1.

  2. Question
    Where are protons, neutrons and electrons found?
    Answer

    Protons and neutrons in the nucleus; electrons around the nucleus.

  3. Question
    What is the atomic number, Z?
    Answer

    The number of protons in the nucleus. It identifies the element.

  4. Question
    What is the mass number, A?
    Answer

    The number of protons + neutrons in the nucleus.

  5. Question
    How do you find the number of neutrons?
    Answer

    Neutrons = mass number − atomic number (A−ZA - Z).

  6. Question
    How many neutrons are in sodium-23 (Z = 11)?
    Answer

    23 − 11 = 12 neutrons

  7. Question
    How does an atom become a positive ion?
    Answer

    By losing electrons. The number of protons does not change.

  8. Question
    How many electrons are in CaX2+\ce{Ca^{2+}} (Z = 20)?
    Answer

    20 − 2 = 18 electrons

  9. Question
    What are isotopes?
    Answer

    Atoms of the same element (same number of protons) with different numbers of neutrons.

  10. Question
    Where is almost all of an atom's mass?
    Answer

    In the nucleus. Electrons have very little mass (about 1/1836 of a proton).

  11. Question
    Why is the atomic mass of chlorine (35.45) not a whole number?
    Answer

    It is an average over chlorine's naturally occurring isotopes (chlorine-35 and chlorine-37).