Calcium has 20 protons, 20 neutrons, and 20 electrons. What is the atomic number of calcium?

A. 20

B. 40

C. 60

8 Answers

  • 1 decade ago
    Best Answer

    Count the protons to get the atomic number. So the answer is A: 20. 40 will be the atomic mass in this situation.

  • 4 years ago

    neutrons= 40-20=20 protons=20 electrons=20 neutrons=atomic mass- atomic number protons= atomic number electrons= same as protons.

  • 1 decade ago

    The answer's 20. The atomic number is the amount of protons in one atom of the element. The atomic number of an element is on the periodic table, too.

  • 1 decade ago

    It's 20. Atomic number refers to the number of protons in the atom.

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  • 1 decade ago


    Source(s): BEST ANSWER
  • 1 decade ago

    20. its so simple. why would you ask that? look i answered your question with another.

  • Sean
    Lv 5
    1 decade ago


  • 1 decade ago


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