5.1 electron structure

formula dictating max electrons in a shell

2n²

define atomic orbital

region around the nucleus that can hold up to 2 electrons with opposite spins

As shell number increases, what happens to the radius of the s-orbital?

increases

As shell number increases, what happens to the p-orbital?

further from the nucleus

define sub-shell

within a shell, orbitals of the same type are grouped together

within a shell, what energy does each additional sub-shell have?

higher energy

why does the 4s sub-shell fill and empty before the 3d sub-shell?

3d sub-shell is at a higher energy level than the 4s sub-shell

why do electrons in an orbital have to have opposite spins?

to counteract the repulsion between the negative charges of the electrons

what elements are the exceptions to the filling order?

Chromium, Copper

Chromium electron configuration

1s2 2s2 2p6 3s2 3p6 4s1 3d5

copper electron configuration

1s2 2s2 2p6 3s2 3p6 4s1 3d10

why are copper and chromium exceptions?

half filled or fully filled sub-shells are more stable

method for writing the electron configuration of positive ions past calcium:

• write the electron configuration as an atom

• count the number of electrons in the ion

• subtract the difference from the 4s sub-shell first and then the 3d.

Define shell

A group of atomic orbitals with the same principal quantum number n

why is electronic configuration an example of a periodic trend? (2)

• same pattern of filling of subshells repeated in other periods

• elements in the same period have the same number of shells

which two elements contain five unpaired d electrons?

Mn Cr