theory first half

Question 1

give the order of specifc charges of an electron, proton, neutron and alpha particle

Answer 1

e⁻ (1840) > p⁺ (1) > α (0.5) > n⁰ (0)

electon > proton > alpha > neutron

Question 2

e⁻ ejected from metal depends upon intensity. True/False

Answer 2

False, depends upom frequency.

however, number of electrons ejected depend upon intensity.

Question 3

only valid part of Rutherfords theory

Answer 3

nucleus

Question 4

acc to rutherford, electron loses energy while orbitting the nucleus, sets on a spiral path and atom should technically collapse acc to EM priniciples. Give flaw of argument.

Answer 4

He assumed energy is lost CONTINUOUSLY.
planck gave the quantisation of energy which said energy loss/gain is DISCONTINUOUS (it is lost/gained in packets i.e. quanta)

Question 5

Bohrs theory was based on? What was his contribution?

Answer 5

Plancks quantum theory.

He gave ‘orbits’ i.e. specific energy levels that an electron inhabits (orbit,place?) or exhibits (energy)

he also gave the quantisation of angular momentum and synthesised the mathematical framwork for the theory too

Question 6

Stationary orbit?

Answer 6

orbits have a specific energy level

Question 7

what do electrons exhibit when they move up and down wrt thermodynamics

Answer 7

up is endothermy

down is exothermy

Question 8

an electon closest to the nucleus will have maximum TE or PE?

Answer 8

neither. it will have maximum KE.

whereas an electorm farthest away from the nucleus will have maximum Potential energy and maximum total energy.

(analogous to gravitational energy)

Question 9

give 3 major drawbacks of Rutherford

Answer 9

1) . energy loss is continuous
2) . no specific arrangement or placement of electrons
3) . no spectrum

Question 10

what is a black body

Answer 10

that which can emit or absorb all types of frequencies

Question 11

limitations of Bohr

Answer 11

1) . maaaaajor= Heisenbergs uncertainty principle was not satisified
2) . custom made only one e⁻ species
3) . broadness of spectrum not defined
4) . zeeman and stark effect not defined

Question 12

stark effect

Answer 12

splitting of spectral lines in ELECTRIC field

Question 13

splitting of spectral lines in magnetic field

Answer 13

Zeeman effect

Question 14

order of EM waves from higher frequency to lower

Answer 14

cosmic gamma X U V IR microwave radio

Question 15

particle nature indicatives are

Answer 15

photoelectric effect and black body radiation

Question 16

diffraction and interference indicate

Answer 16

wave character of e

Question 17

What do the four quantum numbers indicate respectively

Answer 17

Principal Quantum number: position of electron in atom along with energy of electron

Azimuthal quantum number: indicates nature of sub she’ll and structure of sub she’ll in which electron is located

Magnetic quantum number: gives the orientation of orbital

Spin quantum number: indicates magnetic moment of system where each electron behaves like a magnet

Question 18

Pauli’s exclusion principle

Answer 18

Each electron has a unique set of values (sort of like an address?) For the four quantum numbers.
No two electrons of the same atom can have the exact same set of values. If three are same, the fourth will be different.

Question 19

Hund’s rule of maximum spin multiplicity

Answer 19

An electron enters an orbital singly before pairing begins to occur and when it does, it takes place in accordance with a system which has maximum spin multiplicity, minimum energy and maximum stability.