electrons in atoms. address of electrons in atoms
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ELECTRONS IN ATOMSELECTRONS IN ATOMS
Address of electrons in atoms
ELECTRONS IN ORBIT ABOUT ELECTRONS IN ORBIT ABOUT
THE NUCLEUSTHE NUCLEUS
e- density (1s orbital) falls off rapidly as distance from nucleus increases
Where 90% of thee- density is foundfor the 1s orbital
ELECTRON DENSITY OF 1s ORBITAL
= fn(n, l, ml, ms)
______________________________ l
for a given value of n, l = 0, 1, 2, 3, … n-1
n = 1, l = 0n = 2, l = 0 or 1
n = 3, l = 0, 1, or 2
Shape of the “volume” of space that the e- occupies
l = 0 s orbitall = 1 p orbitall = 2 d orbitall = 3 f orbital
Schrödinger Wave Equation
l = 0 (s orbitals)
l = 1 (p orbitals)
l = 2 (d orbitals)
ml = -1 ml = 0 ml = 1
ml = -2 ml = -1 ml = 0 ml = 1 ml = 2
Energy of orbitals in a single electron atom
Energy depends only on principal quantum number n
En = -RH ( )1n2
n=1
n=2
n=3
Energy of orbitals in a many-electron atom
Energy depends on n and l
n=1 l = 0
n=2 l = 0n=2 l = 1
n=3 l = 0n=3 l = 1
n=3 l = 2
Fill lowest energy orbitals first (Aufbau principle)
He 2 electrons
He 1s2
Fill lowest energy orbitals first (Aufbau principle)
Li 3 electrons
Li 1s22s1
Fill lowest energy orbitals first (Aufbau principle)
Be 1s22s2
Be 4 electrons
Fill lowest energy orbitals first (Aufbau principle)
B 5 electrons
B 1s22s22p1
Fill lowest energy orbitals first (Aufbau principle)
C 1s22s22p2
C 6 electrons
?
C 6 electrons
C 1s22s22p2
Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
N 7 electrons
N 1s22s22p3
?
Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
N 7 electrons
N 1s22s22p3
Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
O 8 electrons
O 1s22s22p4
Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
F 9 electrons
F 1s22s22p5
Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.
Ne 10 electrons
Ne 1s22s22p6
Hund’s rule: The most stablearrangement of electrons in subshells is the one with the greatest number of parallel spins.
Order of orbitals (filling) in multi-electron atom
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s
Outermost subshell being filled with electrons
Electrons determine all of the chemicalElectrons determine all of the chemicalproperties and some of the physical properties and some of the physical properties of elements.properties of elements.