midterm Flashcards
what is a quantum ?
single indivisible unit
nm to m
10 to the -9
um to m
10 to the -6
how is λ related to frequency ?
λ increases
frequency decreases
how are E and f related
the same
E decreases f decreases
what causes an emission spectrum
electron transfer from higher to lower energy level
what causes an absorption spectrum
electrons move from lower to higher energy levels
what is work function
minimum energy required of the photon to eject electrons from metal surface
what is threshold frequency
minimum frequency of the photon that can release electrons from a metal surface
name the series n= 1 to n=5
n=1 Lyman LBPBP
n=2 Balmer
n=3 Paschen
n=4 Brackett
n=5 Pfund
photoelectric effect
when light radiation falls on a metal surface electrons are ejected
particle nature
de broglie theory
wavelength = h/mu
combined particle and wave nature of electrons
Plancks Equation
E =hf
define orbital
particular area in an atom with 90% probability of finding electrons
define orbit
circular path electron takes around nucleus
node
space where probability of finding electrons is almost zero
principal quantum number (n)?
signifies size of shell and energy of electron in that shell
angular quantum number (l)
gives info about the shape of orbital
l =0 s orbital
=1 p orbital
=2 d orbital
=3 f orbital
magnetic quantum number (ml)
signifies orientation of orbital
depend on l #
spin quantum number
+ or - 1/2
shielding effect
inner orbital electrons act as a shield between the nucleus and the outer orbital electrons. Due to this, the outer orbital electrons experience lesser nuclear attraction
pauli exclusion principle
no two electrons can have same quantum number
hunds rule
in degenerate orbitals the most stable electrons are ones with parallel spins
aufbau principle
building up
one proton added to nucleus
one electron to orbitals
