Electrons And Bonding 2.5 Flashcards
Orbitals
A region around the nucleus that can hold up to two electrons, with opposite spin.
Why must electrons have opposite spins?
The opposite spins help to counteract repulsion between the negative charges of the two electrons.
Why does 4s sub-shell fill before the 3d?
4s has a lower energy level
Ionic bonding
The electrostatic attraction between positive and negative ions.
What is the arrangement of a giant ionic lattice?
- Regular cubic arrangement
- Each ion is surrounded by oppositely charged ions
Why can most ionic compounds dissolve in water?
Water molecules are polar so they can attract the positive and negative ions and break up the structure.
In which state can ionic compounds conduct electricity?
When molten or dissolved a in solution as the ions can move around because the solid ionic lattice has broken down.
Why can’t electricity be conducted in a solid state?
The ions are in fixed position so there are no mobile charge carriers.
Why are ionic compounds solid at room temperature?
There is insufficient energy required to overcome the strong electrostatic forces of attraction between the oppositely charged ions in the giant ionic lattice.
Why do ionic compounds have high melting and boiling points?
High temperatures are needed to overcome the strong electrostatic attraction between the oppositely charged ions.
Covalent bonding
The strong electrostatic forces of attraction between a shared pair of electrons and the nuclei of the bonded atoms.
Dative covalent bonds or coordinate bond.
A covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms only. E.g lone pair on a nitrogen in ammonia
