An atom with 15 protons, 15 neutrons, and 15 electrons.
Radium has 88 electrons. The number of neutrons is different for each isotope: Number of neutrons = Atomic mass of an isotope - 88
Promethium has 61 protons and electrons; For each isotope the number of neutrons is different. Number of neutrons = Mass number of an isotope - 61
An isotope is an element with the same number of electrons and protons different number of neutrons.
Oxygen has 8 electrons and protons. The number of neutrons is different for each isotope: Number of neutrons = Atomic mass of the isotope - Number of protons
The number of neutrons is the difference between the atomic mass of an isotope and the atomic number. Actinium has a great number of isotopes, each with a different mass or number of neutrons.
Technetium has 43 protons and 43 electrons. For each isotope the number of neutrons is different. Number of neutrons = Mass number of an Tc isotope - 43
Protactinium has 91 protons and electrons; the number of neutrons is different for each isotope: Number of neutrons = Atomic Mass of the isotope - 91
Nickel have 28 protons and electrons and a different number of neutrons for each isotope..
Nickel has 28 protons and electrons; the number of neutrons is different for each isotope.
Radium has 88 electrons. The number of neutrons is different for each isotope: Number of neutrons = Atomic mass - 88 The most stable and known isotope of radium, 226Ra, has 138 neutrons.
Technetium has 43 protons and 43 electrons. For each isotope the number of neutrons is different. Number of neutrons = Mass number of an Tc isotope - 43
Number of neutrons = Atomic mass of an isotope - Atomic number of the element The atomic number of meitnerium is 109. Each isotope of an element has a different number of neutrons.