electrons and bonding

what are shells

the energy levels/the regions around the nucleus where electrons are most likely to be

what is the formula to work out number of electrons in a shell - n=the shell number

2n² - 2x(n²)

how many electrons can the first 4 shells fit

1 - 2

2 - 8

3 - 18

4 - 32

what is an orbital

a region around the nucleus where 2 electrons can be found (with opposite spins)

what are the 4 types of orbital

S, P, D, F

what shape is an s-orbital

a sphere

how many s-orbitals are there per shell

1

what shape is a p-orbital

a dumbbell shape

how many p-orbitals per shell

3 - one for each direction (only from shell 2 onwards)

how many d-orbitals per shell

5 (only from shell 3 onwards)

how many f-orbitals per shell

7 (only from shell 4 onwards)

shell and orbital table

each new shell gains a new type of orbital

what’s the difference between orbitals and sub-shells

sub-shells are groupings of orbitals

orbital - the space around a nucleus that has a chance of an electron being there

sub shell - the path taken by electrons as they move

how are orbitals filled + example

by increasing energy

energy levels of sub shells 1-4

this means the 4s sub shell will fill before the 3d sub shell

what is spin

a property an electron has referring to its momentum (don’t need to know what it is just that electrons have it)

what are the 2 types of spin

up spin and down spin

electrons pairs and spin

electron pairs have to have opposite spin as it counteracts the repulsion between the negative charges

when putting electrons in orbitals how are they placed

putting 1 in each orbital before pairing them

how to draw electron configuration - example

what is shorthand electron configuration

writing the previous noble gas then carrying on the electron configuration so you don’t have to write it all down

how do you represent ions using electron configuration

you add or remove electrons from the highest energy sub shell

example of calcium and oxygen ions