# ELECTRONS IN ATOMS Address of electrons in atoms ELECTRONS IN ATOMS Address of electrons in atoms ELECTRONS IN ORBIT ABOUT THE NUCLEUS ELECTRON DENSITY OF 1s ORBITAL

Where 90% of the e- density is found for the 1s orbital e- density (1s orbital) falls off rapid as distance from nucleus increases Schrdinger Wave Equation

= fn(n, l, ml, ms) ______________________________ l or a given value of n, l = 0, 1, 2, 3, nl n = 1, l = 0 l n = 2, l = 0 or 1 l n = 3, l = 0, 1, or 2

l = = = = 0 1

2 3 s p d f orbital

orbital orbital orbital Shape of the volume of space that the e - occupies l = 0 (s orbitals) l = 1 (p orbitals)

l = 2 (d orbitals) ml = -1 ml = -2 ml = 0

ml = -1 ml = 0 ml = 1 ml = 1 ml = 2

Energy of orbitals in a single electron atom Energy depends only on principal quantum number n n=3 n=2 En = -RH (

n=1 1 n2 ) Energy of orbitals in a many-electron atom Energy depends on n and l

n=3 l = 2 n=3 l = 0 n=2 l = 0 n=1 l = 0 n=3 l = 1 n=2 l = 1

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 4 electrons Be 1s22s2 Fill lowest energy orbitals first (Aufbau principle)

B 5 electrons B 1s22s22p1 Fill lowest energy orbitals first (Aufbau principle) ? C 6 electrons C

1s22s22p2 s rule: The most stable arrangement of rons in subshells is the one with the greate r of parallel spins. C 6 electrons C

1s22s22p2 s rule: The most stable arrangement of rons in subshells is the one with the greate r of parallel spins. ? N 7 electrons N

1s22s22p3 s rule: The most stable arrangement of rons in subshells is the one with the greate r of parallel spins. N 7 electrons N

1s22s22p3 s rule: The most stable arrangement of rons in subshells is the one with the greate r of parallel spins. O 8 electrons O

1s22s22p4 s rule: The most stable arrangement of rons in subshells is the one with the greate r of parallel spins. F 9 electrons F

1s22s22p5 Hunds rule: The most stablearrangement of electrons in subshells is the one with the greatest number of parallel spins. Ne 10 electrons Ne

1s22s22p6 er of orbitals (filling) in multi-electron a < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < utermost subshell being filled with electron

rons determine all of rties and some of the rties of elements. the chemi physical