2.2 Atomic Models

Question 1

Who proposed the first atomic model?

Answer 1

J.J. Thomson

Question 2

Explain Thomson’s Atomic Model

Answer 2

• Atom is a sphere of uniformly distributed positive charge with a no. of electrons embedded into it

Question 3

Who did the “alpha particle scattering” experiment?

Answer 3

Rutherford

Question 4

Explain Rutherford’s Atomic Model.

Answer 4

• Atom has a very small positively charged centre known as the ‘nucleus’ and electrons revolve around it in circular orbits.

Question 5

According to X-ray studies, Nucleus has a radius of an order of?

Answer 5

10^-15 m

Question 6

According to X-ray studies, Atom has a radius of the order of?

Answer 6

10^-10 m

Question 7

What is the order of penetration power of α-rays, β-rays, γ-rays X-rays?

Answer 7

α-rays < β-rays < X-rays < γ-rays

Question 8

What are Isotopes?

Answer 8

Different atoms of same element having same atomic number but different mass number

Question 9

What are Isobars?

Answer 9

Atoms of different element having same mass number but different atomic number

Question 10

What are Isotones?

Answer 10

Atoms of different elements containing same number of neutrons

Question 11

What are Isodiapheres?

Answer 11

Atoms having same isotopic number.
(isotopic number = no. of neutrons - no. of protons)

Question 12

What are Isosteres?

Answer 12

Molecules having same number of atoms and electrons.

Question 13

What are Isoelectronic species?

Answer 13

Those species which have same number of electrons.