Atoms

Question 1

What is the distance of closest approach?

Answer 1

Distance of closest approach is the distance of the alpha particle from the nucleus at which the entire kinetic energy of the alpha particle is converted into its electrostatic potential energy.

Question 2

What is Impact Parameter?

Answer 2

The perpendicular distance of the initial velocity vector of the alpha particle from the centre of the nucleus is impact parameter.

Question 3

Bohr’s postulates

Answer 3

1.An electron in an atom could revolve in certain stable orbits without the emission of radiant energy.
2.Electrons revolve around the nucleus only in those orbits for which the angular momentum is some integral multiple of h/2pi
3.An electron emits or absorbs radiation when it jumps from a higher energy orbit to a lower energy orbit or from a lower energy orbit to a higher energy orbit respectively.

Question 4

What is ground state?

Answer 4

The energy state corresponding to n=1, has the lowest energy equal to -13.6 eV. This state or orbit is called the ground state or normal state of the atom.

Question 5

What is ionization energy?

Answer 5

The minimum amount of energy required to remove an electron from its ground state is called ionization energy.

Question 6

Wave number formula.

Answer 6

v = R [1/nf2 - 1/ni2]

Question 7

Energy Formula

Answer 7

E = -13.6/n2 eV

Question 8

Radius formula

Answer 8

r = a0(n2) where a0 = 0.53 A