a. 7 protons, 7 electrons, 10 neutrons
b. 19 protons, 19 electrons, 26 neutrons
c. 53 protons, 53 electrons, 84 neutrons
Given
Atom and mass number
Required
The number of each subatomic particle
Solution
a. Nitrogen atom(atomic number = 7)
mass number = 17 amu
atomic number=number of protons=number of electrons(in neutral atom)
so number of protons=number of electrons = 7
mass number = protons+neutron
17 = 7 + neutrons
number of neutrons = 17-7=10
b. Potassium atom (atomic number = 19)
mass number = 45 amu
atomic number=number of protons=number of electrons(in neutral atom)
so number of protons=number of electrons = 19
mass number = protons+neutron
45 = 19 + neutrons
number of neutrons = 45-19=26
c. Iodine atom ((atomic number = 53)
mass number = 137 amu
atomic number=number of protons=number of electrons(in neutral atom)
so number of protons=number of electrons = 53
mass number = protons+neutron
137 = 53 + neutrons
number of neutrons = 137-53=84