Electrons, Bonding and Structure Flashcards
How are shells described and how many are there?
Energy levels and 4
How many electrons can each sub-shell hold:
- s =
- p =
- d =
- f =
- s = 2
- p = 6
- d = 10
- f = 14
How many electrons do each shell hold?
2.8.18.32
General formula of how many electrons can fit into each shell:
What’s the order of filling the electric configuration?
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p
What is the big number in electronic configurations?
The principal quantum number
What are the exceptions of the electronic configuration rules?
What are orbitals?
An orbital is a region around the nucleus which can hold up to a maximum of 2 electrons, with opposite spin
What shape is an s-orbital?
Spherical
What shape is a p-orbital?
Dumbbell
Noble gases:
- Group 0 (or 18) of the periodic table
- They exist as individual atoms (monatomic)
- Their outer shells contain 8 electrons (except Helium which contains 2)
- All their electrons are in pairs
- They are very stable and unreactive/inert
Bonding:
- Atoms combine in order to get the same electron arrangement as a noble gas i.e. 8 electrons in their outer shell (this is called the octet rule)
- They do this by sharing or transferring electrons to form chemical bonds
What is a compound?
A compound is a substance formed when 2 or more different elements chemically bond together in a fixed ratio
What is an ionic bond?
An ionic bond is the electrostatic force of attraction between positive and negative ions e.g. NaCl
What is a covalent bond?
A covalent bond is the strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms e.g. CO2
What is metallic bonding?
Metallic bonding is the strong electrostatic force of attraction between positive metal ions and delocalised outer electrons e.g. copper
Ionic bonding of Na and O
Covalent bonding of P and H
Ionic (and covalent) bonding of NaOH
Exceptions to the octet rule: electron deficiency
Exceptions to the octet rule: expanding the octet
Which elements cannot expand their octet?
Period 2 elements (e.g. N, O, F) cannot expand their octet because they don’t have an f or d sub-shell, and therefore cannot hold more than 8 electrons in their outer shell