1) List the number of each subatomic particle in the following atoms (1 point): a) A nitrogen atom with a mass of 17 amu.
b) An atom of potassium with a mass of 45 amu.
c) An atom of iodine with a mass of 137 amu.

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