Chemistry Class 11 NCERT Solutions: Chapter 2 Structure of Atom Part 2

Q: 3. How many neutrons and protons are there in the following nuclei?

Equation

This structure is atomic number of an element then we also know how many protons in an element

Image of Neutrons, Protons & Electron

This structure is atomic number of an element then we also know how many protons in an element

Answer:

Equation

Atomic mass = 13

Atomic number = Number of protons = 6

Number of neutrons = (Atomic mass) -(Atomic number)

Equation

Equation

Atomic mass = 16

Atomic number = 8

Number of protons = 8

Number of neutrons = (Atomic mass) Equation (Atomic number)

Equation

Equation

Atomic mass = 24

Atomic number = Number of protons = 12

Number of neutrons = (Atomic mass) Equation (Atomic number)

Equation 12 = 12

Equation

Atomic mass = 56

Atomic number = Number of protons = 26

Number of neutrons = (Atomic mass) Equation (Atomic number)

Equation 26 = 30

Equation

Atomic mass = 88

Atomic number = Number of protons = 38

Number of neutrons = (Atomic mass) - (Atomic number)

Equation

Q: 4. Write the complete symbol for the atom with the given atomic number (Z) and Atomic mass (A)

(i) Equation

(ii) Equation

(iii) Equation

Answer:

(i) Equation

Equation Equation

(iii) Equation

Q: 5 Yellow light emitted from a sodium lamp has a wavelength Equation Calculate the frequency and wave number Equation of the yellow light.

Answer:

From the expression,

Equation

We get,

Equation

Where,

Equation

Wavelength of yellow light Equation

Substituting the values in expression (i):

Equation

Thus, frequency of yellow light emitted from the sodium lamp

Equation

Wave number of yellow light, Equation

Equation

Explore Solutions for Chemistry

Sign In