May 05, 2025
Non-metal forms gain electrons as they have a high effective nuclear charge.
May 05, 2025
Metal atoms lose electrons.
May 05, 2025
- Does not readily form ions (Except lead and silver). Have four valence electrons -> energetically unfavourable to lose or gain four electrons to achieve a noble gas configuration.
May 05, 2025
- Ions with a charge greater than 3+ due to large charge density.
- polarise negative ions
May 05, 2025
- The charge can be deduced from the number of hydrogens in the formula of the corresponding acid.
E.g HNO3 charge of nitrate = -1
H2CO3 charge of carbonate = -2
- Covalent bonding
May 06, 2025
- Lattice structure
- Held by ionic bond
- Involves a fixed arrangement of ions based on repeating UNIT/UNIT CELL (not molecules).
- No fixed number of ions so formulas are rations of ions present.
- Has a coordination number
- Electrically neutral -> Total net charge 0
May 06, 2025
Pairs of electrons are arranged so that each atom gains a full valence shell.
May 07, 2025
- Deduce how many by looking at the number of possible positions for its double bond(s).
- Lone pairs are not drawn as delocalised (no fix position).
May 07, 2025
the difference in energy between the actual molecule and a hypothetical structure with localized bonds.
e.g benzene theoretical = -362 kJ/mol
Experimental = -210 kJ/mol
resonance energy = -210--362= 152kJ/mol
May 07, 2025
FC = V - (0.5B + L)
If structures have the same difference of formal charge. A negative charge on the more electronegative atom is more stable.
May 07, 2025
Overlap of a hybrid orbital with any other atomic orbital always forms a sigma bond.
May 09, 2025
Every electron spin acts as a tiny magnet. When the electron is unpaired the net magnetic effect is not canceled out.