Chapter 5 - Electrons & Bonding Flashcards
What are shells regarded as?
Energy levels
What happens to energy as the shells increase
Energy increases
What is shell number (n) also known as?
Principle quantum number
How do you work out the number of electrons in each shell?
2(n^2)
What are orbitals? Definition?
Make up the sub shells which make up the shells
Region of space around nucleus that can hold up to 2 paired electrons with opposite spins
How many electrons can each orbital hold? What are the different types of orbitals?
2 electron s
s, p, d, f
What shapes are the s and p orbitals?
s = sphere (greater the shell number the larger the radius)
p = dumbbell ( greater the shell number the farther the orbital from the nucleus)
Which orbitals are in each shell?
n = 1: 1s
n = 2: 2s + 3 x 2p
n = 3: 3s + 3 x 3p + 5 x 3d
n = 4: 4s + 3 x 4p + 5 x 4d + 7 x 4f
Which shell and orbitals have the highest energy?
fourth = highest energy
f orbital = highest energy
What are the 3 rules of filling the orbitals?
RULE 1:
- orbitals fill in order of increasing energy
- EXCEPT 4s fills before 3d
RULE 2:
- electrons pair with opposite spins (up and down)
- represented by arrows
- to minimise repulsion
RULE 3:
- orbitals with the same energy (subshell orbitals) are occupied singularly first
- prevents repulsion until no other orbitals are available
What is the shorthand notation for electron configuration?
Previous noble gas plus the outer electron sub shells
Na: [Ne] 3s1
How do we write the electron configuration of ions?
Once filled, 4s becomes higher in energy than 3d orbital so the electrons in 4s are lost before 3d even though it fills first
Write 3d before 4s for ions
What is the electrostatic force of attraction between in ionic bonding?
The oppositely charge ions in all directions
What is the definition of ionic bonding?
The electrostatic force of attraction between oppositely charged ions in all directions to form a giant ionic lattice
What affects the MP/BP of ionic compounds?
Ionic charge - greater charge means stronger electrostatic forces so a higher MP/BP
Ionic radius - smaller the ionic radius means the stronger the electrostatic force so higher MP/BP
What is the pattern for size of ionic radii down the group?
Increases in size down the group
Which isoelectronic ions have smaller ionic radii?
Ones with the most protons as the nucleus would have stronger electrostatic forces of attraction with the electrons pulling the ionic structure closer together
How do ionic compounds dissolve in water? Pattern for solubility?
The water molecules break down the lattice and surround each ion in the solution
Greater ion chargers = reduced solubility
Definition of a molecule?
Smallest part of a covalent compound that can exist while retaining the chemical properties of the compound
How do you know how many covalent bonds an atom can form?
Number of electrons it needs to have a full outer shell
What are dative covalent bonds? Another name for them?
A covalent bond where the shared pair of electrons have been supplied by one of the bonding atoms only
They were originally a lone pair of electrons
Coordinate bonds
How are dative covalent bonds represented in a displayed formula?
By an arrow from the one supplying to the bonded one
What is 1 unusual case for covalent bonding?
Expanding the octet -> more electrons in the outer shell as they’re are more orbitals available
What are reasons why some have full outer shells of 18 electrons?
- Limited by size of the atom
- number of electrons available from atom
