✨Module 2: Electrons and bonding Flashcards
Electron shells are also known as …
Electron shells are made up of …
Energy levels.
Sub-shells and orbitals.
Each shell is given a principal …
Quantum number - shell number ‘n’.
Electrons have fixed …
Energies and move around in shells.
Shells further form the nucleus have …
Higher energy, larger prin quantum number, and hold more electrons.
What are sub-shells?
Divisions within electron shells, each having a different energy.
Subshells include …
S, p, d, f, which have different number of orbitals, so a shell is a group of atomic orbitals.
Define atomic orbital.
Region around the nucleus that can hold up to 2 electrons with opposite spins.
Maximum number of electrons in a shell?
2n^2. So 1st = 2, 2nd = 8, 3rd = 18, 4th = 32.
Noble gases can be used in …
Shorthand electron configurations, but only when asked.
Define ionic bond.
Strong electrostatic force of attraction between oppositely charged ions.
Ions with greater charge will have …
Greater attraction to other ions so stronger ionic bonding.
Larger ions with a greater ionic radius …
Will have weaker attraction as the attractive forces act over a greater distance.
Higher charge increases boiling point but …
Decreases solubility as water molecules can’t overcome electrostatic forces.
Define covalent bond.
Shared pair of electrons between 2 atoms and attracted to the nuclei of both atoms.
What is ‘expand the octet’?
When the atom is able to have more than 8 valence electrons. Like sulfur hexafluoride has 12 electrons in its outer shell, PCL5.
Why do shorter covalent bonds tend to be stronger?
Atoms are held closer together so forces of attraction are stronger, requiring more energy to overcome.
Double and triple covalent bonds are shorter than single covalent bonds as …
There’s more attraction between atoms and more electrons, so stronger bonds.
What is average bond enthalpy?
Energy required to break a bond. It is used to measure covalent bond strength.
The stronger the bond …
The greater the average bond enthalpy as more energy is required to break it.
What is a dative covalent bond?
When both electrons in the shared pair are supplied from one atom.
For a dative covalent bond to form the …
Acceptor atom must be electron deficient.
