Module 2.2 electrons, bonding and structure Flashcards
Principal quantum numbers
The numbers given to shells
shells further away from the nucleus have
higher energy (larger principal quantum number) than shells closer to the nucleus
types of sub shell with number of orbitals and maximum electron capacity
s sub shell. 1 orbital. max e- = 2
p sub shell. 3 orbitals. max e- –> 3 x 2 = 6
d sub shell 5 orbitals. max e- –> 5 x 2 = 10
f sub shell 7 orbitals max e- –> 7 x 2 = 14
how many electrons can one orbital carry
2
shell, what sub-shells it contains and total no,. of electrons
1st: 1s total e- = 2
2nd: 2s 2p total e- : 2+(3x2) = 8
3rd: 3s 3p 3d total e- : 2 + (3x2)+ (5x2) = 18
4th: 4s 4p 4d 4f total e-: 2+ (3x2) + (5x2) + (7x2) = 32
1st shell: sub shells and total number of electrons
1st
sub-shell: 1s
total e- : 2
2nd shell: sub shells and total number of electrons
2nd
sub-shells: 2s 2p
total e- : 2 + (3x2) = 8
3rd shell: sub shells and total no. of electrons
3rd
sub-shells: 3s 3p 3d
total e- : 2 + (3x2) + (5x2) = 18
4th shell: sub shells and total no. of electrons
4th
subshells: 4s 4p 4d 4f
total e- : 2 + (3x2) + (5x2) + (7x2) = 32
total no. of electrons in 1st shell
2
total no of e- in 2nd shell
8
total no of e- in 3rd shell
18
total no of e- in 4th shell
32
sub-shell s: no. of orbitals and max no. of e-
and shape
s
orbitals = 1
max e- = 2
shape = spherical
sub shell p: no of orbitals and max no. of e-
and shape
p
orbitals = 3
max e- = 6
shape= three dumbbell shaped orbitals at right angles to one another
sub-shell d: no. of orbitals and max no. of e-
d
orbitals = 5
max e- = 10
sub-shell f: no. of orbitals and max no. of e-
f
orbitals = 7
max e- = 14
no. of e- in sub-shell s
2
no. of e- in sub-shell p
6
no. of e- in sub shell d
10
no. of e- in sub-shell f
14
what is an orbital
is a bit of space in which the electrons move in. orbitals within the same sub shell have the same energy.
spin of electrons in orbitals
orbitals contain 2 electrons each.
they spin in opposite directions
spin pairing
order in which shells fill
1s - 2s - 2p - 3s - 3p - 4S- 3D - 4p - 4d - 4f
main point: 4s fills before 3d
why does 4s fill before 3d
because 4s has a lower energy level than 3d even though its principle quantum number is bigger.
how do electrons fill orbitals in a sub shell
electrons fill orbitals singling before they start sharing
how are noble gas symbols used in sub shell notation
noble gas symbols like argon (Ar)
which e- configoration is: 1s(2) 2s(2) 2p(6) 3s(2) 3p(6)
are sometimes used .
e.g calcium: 1s(2) 2s(2) 2p(6) 3s(2) 3s(2) 3p(6) 4s(2) can be written as: [Ar] 4s(2)
define ionic bond
is an electrostatic attraction between two oppositely charged ions
electrostatic attraction
is the force that holds -ve and +ve ions together
sodium chloride structure:
giant ionic lattice
basic repeat unit of Na+ and Cl-
it foms becacuse each ion is electrostatically attracted in all directions to ions of opposite charge.
cine shape
melting point of sodium chloride
is extremely high (801 oc) because of the very strong ionic bonds