GK
CHEMISTRY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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15 protons
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30 protons
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10 protons
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None of the above
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Detailed explanation-1: -Answer and Explanation: The atomic number of an element is the number of protons in the nucleus of the atom. Therefore, the atom with an atomic number of 15 must have 15 protons in the nucleus.
Detailed explanation-2: -therefore, protons in nucleus of phosphorus are 15.
Detailed explanation-3: -Nitrogen 15 has an atomic mass of 15. The mass number is # protons plus # of neutrons, so for N-15 mass is 15 and the protons are always 7 so there have to be 15-7=8 neutrons.
Detailed explanation-4: -So, this element has 15 protons (atomic number), 15 electrons, and 16 neutrons (mass number minus atomic number). This isotope is phosphorus-31, which has atomic number 15.
Detailed explanation-5: -of neutrons = mass no.-no. of protons = 31-15 = 16.