Atomic Structure

Question 1

What are the postulates of Dalton’s Atomic Theory?

Answer 1

1. Atom is the smallest indestructible individual unit of matter.
2. Atoms of a particular element are different from atoms of other elements.
3. Atoms are combined in simplest whole number ratio.
4. Atoms cannot be created or destroyed.

Question 2

Relation of energy and wavelength(λ)

Answer 2

E = hc/λ

Question 3

Order of different types of rays based on energy

Answer 3

Cosmic<Yrays<X rays< Ultra-violet rays < Visible< Infrared< Microwave< Radiowave

Question 4

What is work function?

Answer 4

Minimum amount of energy required for ejection of electrons from a surface of metal

Question 5

What is threshold frequency?

Answer 5

Minimum frequency of incident radiations below which no emission takes place

Question 6

Relation b/w Energy, work function and KE

Answer 6

E = Work Function + KE

Question 7

Stopping Potential

Answer 7

Minimum potential required by which the movement of electron from cathode to anode

Question 8

mvr =

Answer 8

mvr = nh/2 pi

Question 9

Radius of the nth orbit

Answer 9

0.529n^2/Z

Question 10

Velocity of an electron

Answer 10

2.18*10^8 Z/n

Question 11

What is the energy absorbed if the atom moves from n1 to n2?

Answer 11

13.6 z^2(1/n1^2 - 1/n2^2)

Question 12

Ionisation Energy

Answer 12

Energy required to promote an electron from n=1 to n = infinity
I.E. = 13.6Z^2

Question 13

Ionisation Potential

Answer 13

Potential required to eject an eletron from n = 1 to n = infinity

Question 14

Excitation Energy

Answer 14

Energy for ejecting an electron n =1 to any other excited state
E.E. = 13.6 Z^2(1 - 1/n^2)

Question 15

What is the ratio between KE, PE, and TE?

Answer 15

1:-2:-1

Question 16

Separation Energy

Answer 16

Energy required to eject an electron from any excited state to infinity
S.E. = 13.6*Z^2/n^2

Question 17

Regions in hydrogen spectrum

Answer 17

Lyman, Balmer, Paschen, Bracket, P-fund, Humphrey

Question 18

Maximum number of emission lines

Answer 18

n(n-1)/2

Question 19

Wavelength of a moving particles with velocity v

Answer 19

λ = h/mv

Question 20

Nodes and Antinodes

Answer 20

Nodes are the region around the nucleus where the probability of finding electrons is 0, whereas antinodes are the region around the nucleus where the probability is maxima.

Question 21

What are the values of l?

Answer 21

0 to n-1

Question 22

What are the values and total number of values of m?

Answer 22

-l to l, the total number of values = 2l +1

Question 23

Orbital Angular Momemtum

Answer 23

root l(l+1) h/2pi

Question 24

Magnetic Moment

Answer 24

root n(n+2) B.M.

Question 25

Aufbau’s Principal

Answer 25

Electrons will be filled in various subshells according to their increasing energy

Question 26

Bohr’s Bury Rule

Answer 26

Electrons will enter that subshell in the very first place whose n+l value is smaller

Question 27

Hund’s Rule

Answer 27

Pairing of electrons will not take place until/unless every orbital is not singly filled

Question 28

Pauli’s Exclusion Principle

Answer 28

No two electrons in an atom can have the same set of all four quantum number