Question

The following are the properties of isotopes of two elements that are essential in our diet. Determine the number of protons, neutrons and electrons in each and name them.

(a) atomic number 26, mass number 58, charge of 2+
(b) atomic number 53, mass number 127, charge of 1-

Answer 1

a) Protons = 26, neutrons = 32, electrons = 24

b) Protons = 53, neutrons = 74, electrons = 54

Step-by-step explanation:

For neutral atoms:

Atomic Number (Z)= number of protons = number of electrons-----(1)

Mass number (A) = number of protons + number of neutrons-----(2)

For ions with positive net charge:

Number of electrons = Z - net charge -----(3)

For ions with negative net charge:

Number of electrons = Z + net charge ----(4)

a) Z = 26, A = 58, Charge = +2

From equation (1):

Number of protons = 26

From equation (2)

Number of neutrons = A-Z = 58-26 = 32

From equation (3):

Number of electrons = Z - 2 = 26-2 = 24

b) Z = 53, A = 127, Charge = +1

From equation (1):

Number of protons = 53

From equation (2)

Number of neutrons = A-Z = 127-53 = 74

From equation (4):

Number of electrons = Z + 1 = 53+1 = 54