Isotopes- ! it’d be much more appropriated if you added an explanation so i understand rather than just an answer!

13.

a.Atomic number of cadmium is 48

b.Number of protons = 48

c.Mass number = 115 u

d.Number of neutrons=67

e.Isotopic Symbol=

14. Elements which are isotopes are:

Explanation:

13.

a.Atomic number(Z):The number of protons present in the nucleus of the atom. Every element have fixed characteristic atomic number which decides its chemical property.It is represented by Z

for example : hydrogen atomic no. is 1 ,He is 2

So Cadmium has attained 48 atomic number.

b.Number of protons = Atomic number of the element

The atomic number of Cadmium is 48. Hence

Number of protons in Cadmium=48

c.Mass number(A) = Total number of protons and neutrons present in the nucleus of the atom.It is represented by A

Mass number = number of proton + number of neutron.....(1)

Cadmium has mass number of 115

d.Using equation (1),

Number of neutron = mass number - number of proton

Number of protons in Cadmium=48

Cadmium has mass number = 115

Number of neutron = 115 - 48

                                  =67

e.The format of symbolic representation of elements is given below

where X=symbol of element

Z= Atomic number

A= mass number

For Cadmium , X = Cd,Z = 48 , A =115

Symbol=

(Since this is isotope of cadmium hence it is isotopic symbol)

14.

Isotopes: These are the species which have same number of protons(or atomic number) but different number of neutrons(mass number).

So A ,C and E are isotopes

mass number: B=55 ,D=57

B and D are isotopes

im not exactly sure but i think its b!