Bonding, Structure, Periodicity with a hint of electron configuration Flashcards
what is an electron shell?
A group of atomic orbitals with the same principal quantum number, n. Also, known as a main energy level
What are shells made up of?
Atomic orbitals
what is an orbital?
an orbital is a region around the nucleus that can hold up to two electrons, with opposite spins
how many electrons can be held in shell 1?
2
how many electrons can be held in shell 2?
8
how many electrons can be held in shell 3?
18
how many electrons can be held in shell 4?
32
what shape are s obitals?
spherical
what shape are p orbitals?
dumbell
order of size from smallest to largest
electron - orbital - subshell - shell
what are the three rules when filling orbitals?
- Electrons fill the orbitals in increasing energy
- No more than two electrons with OPPOSITE spins can occupy a single orbital
- Electrons spread out occupying as many orbitals with similar energy as possible, before filling orbitals with another electron
what are the subshells? how many lectrons do they hold?
s = 2 p = 6 d = 10 f = 14
what is the special area when filling subshell?
4s fills before 3d
what is an ionic bond?
The electronstatic attraction between positive and negative ions
what is a covalnt bond?
A covalent bond is the strong electrostatic attraction between a shared pair of electrons and the nuclei of a bonded atom
what is a dative covalent bond?
A shared pair of electrons in which the bonded pair has been provided by one of the bonding atoms only.
what is metalic bonding?
The strong electrostatic attraction between positive metal ions and a sea of delocalised electrons.
What is electron pair repulsion theory?
Pairs of electrons repel each other as far apart from each other as possible
Lone Pairs repel more than bonding pairs.
2 bonding pairs: name, angle, example and draw
Linear
180°
CO2
3 bonding pairs: name, angle, example and draw
Triagonal planar
120°
BF3
4 bonding pairs: name, angle, example and draw
Tetrahedral
109.5°
CH4
6 bonding pairs: name, angle, example and draw
Octahedral
90°
SF6
3 bonding pairs AND 1 lone pair: name, angle, example and draw
Pyramidal
107°
NH3
2 bonding pairs AND 2 lone pair: name, angle, example and draw
Non-linear
104.5°
H2O
What are the special cases for the atomic shapes?
Treat double bonds like single bonds
Charge doesnt change anything
what do you say if you get a double bond when describing atomic shapes?
Regions of bonding electrons, instead of bonding pairs
How do we explain the atomic shapes/ What do we do to work it out?
- Count and state the number of bonding pairs and lone pairs
- Say ‘Pairs of electrons repel each other as far apart from each other as possible’
- If lone pairs present, say ‘Lone Pairs repel more than bonding pairs’
- State name of the shape and its bond angle.
What is a lone pair?
An outer shell pair of electrons that is not involved in a covalent bond
what is a bonding pair?
A pair of electrons shared between two atoms to make a covalent bond
what does it mean when something is electron deficient? What does this happen to?
When an atom that forms a covalent bond has less than 8 electrons in its outer shell of electrons, e.g BF3
what does it mean when something has expanded its octet
When an atom that forms a covalent bond has more than 8 electrons in its outer shell of electrons e.g SF6
Valency of boron
3
valency of sulfur
2, 4 or 6
valency of chlorine
1, 3, 5 or 7
what are the properties of giant ionic lattices?
melting and boiling point -
High mp and bp, strong electrostatic attarction between ions therfore requireing lots of energy to overcome these bonds
Electrical conductivity -
solid - doenst coduct, ions are fixed and cannot move
molten + aqueous - do conduct, ions are free from the lattice and can move
Solubility in water -
Soluble, ions have charge, and therefore can interact with the dipole on water molecules