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9- How many protons, electrons, and neutrons does an atom with atomic number
50 and mass number 125 contain? *
O A) 50 protons, 50 electrons, 75 neutrons
B) 75 electrons, 50 protons, 50 neutrons
C) 120 neutrons, 50 protons, 75 electrons
D) 70 neutrons, 75 protons, 50 electrons

Respuesta :

xlooqi

Answer:

A

Explanation:

the atomic number means the number of protons so there are 50 protons

the number of positive charges (protons) should equal the number of negative charges (electrons) so there should be 50 electrons

the mass number = neutrons number + protons number

and we knew already that we have 50 protons so the number of neutrons is 125-50=75 neutrons