Atomic Structure Flashcards
What are the postulates of Dalton’s Atomic Theory?
- Atom is the smallest indestructible individual unit of matter.
- Atoms of a particular element are different from atoms of other elements.
- Atoms are combined in simplest whole number ratio.
- Atoms cannot be created or destroyed.
Relation of energy and wavelength(λ)
E = hc/λ
Order of different types of rays based on energy
Cosmic<Yrays<X rays< Ultra-violet rays < Visible< Infrared< Microwave< Radiowave
What is work function?
Minimum amount of energy required for ejection of electrons from a surface of metal
What is threshold frequency?
Minimum frequency of incident radiations below which no emission takes place
Relation b/w Energy, work function and KE
E = Work Function + KE
Stopping Potential
Minimum potential required by which the movement of electron from cathode to anode
mvr =
mvr = nh/2 pi
Radius of the nth orbit
0.529n^2/Z
Velocity of an electron
2.18*10^8 Z/n
What is the energy absorbed if the atom moves from n1 to n2?
13.6 z^2(1/n1^2 - 1/n2^2)
Ionisation Energy
Energy required to promote an electron from n=1 to n = infinity
I.E. = 13.6Z^2
Ionisation Potential
Potential required to eject an eletron from n = 1 to n = infinity
Excitation Energy
Energy for ejecting an electron n =1 to any other excited state
E.E. = 13.6 Z^2(1 - 1/n^2)
What is the ratio between KE, PE, and TE?
1:-2:-1
Separation Energy
Energy required to eject an electron from any excited state to infinity
S.E. = 13.6*Z^2/n^2
Regions in hydrogen spectrum
Lyman, Balmer, Paschen, Bracket, P-fund, Humphrey
Maximum number of emission lines
n(n-1)/2
Wavelength of a moving particles with velocity v
λ = h/mv
Nodes and Antinodes
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.
What are the values of l?
0 to n-1
What are the values and total number of values of m?
-l to l, the total number of values = 2l +1
Orbital Angular Momemtum
root l(l+1) h/2pi
Magnetic Moment
root n(n+2) B.M.
Aufbau’s Principal
Electrons will be filled in various subshells according to their increasing energy
Bohr’s Bury Rule
Electrons will enter that subshell in the very first place whose n+l value is smaller
Hund’s Rule
Pairing of electrons will not take place until/unless every orbital is not singly filled
Pauli’s Exclusion Principle
No two electrons in an atom can have the same set of all four quantum number
