Chapter 5 - Electrons and Bonding Flashcards
Electron structure, Ionic bonding and structure and Covalent bonding.
Shells are regarded as what?
Energy levels
What happens to energy as the shell number increases?
Energy increases
What is the shell number referred to as?
Principal quantum number
What are shells made up of?
Atomic orbitals
How many electrons can be held in an orbital?
One or two, no more.
What are the different orbitals?
S-orbitals
P-orbitals
D-orbitals
F-orbitals
How many orbitals does each type contain?
S - one
P - three
D - five
F - seven
How many electrons can be held in each orbital type?
S - two
P - six
D - ten
F - fourteen
What is the shape of an s-orbital?
Spherical
What is the shape of a p-orbital?
Dumbbell
What are the rules of orbital fillings?
Orbitals fill in order of increasing energy.
Orbitals with the same energy are occupied singly first then pair up with opposite spins.
Where does this rule cause confusion for 3d and 4s?
The 3d sub-shell has higher energy than the 4s.
So the 4s fills before the 3d. Then when the 4s fills up it takes higher energy level than the 3d, so the 4s loses electrons first.
Explain the rule of electrons pair with opposite spins
We know that electrons are negatively charged and so repel one another.
& Electrons also have a property of spin up or spin down.
So what happens is that the electrons pair up with opposite spin, this is so the charge repulsion is counteracted enough for both to be in the orbital.
Explain the rule of orbitals with the same energy which occupy singly first
Within a sub shell, the orbitals have the same energy. One electron occupies each orbital before pairing begins. This prevents repulsion.
How can electron configuration be shortened?
1s2 can be expressed as [He].
1s2 2s2 2p6 can be expressed as [Ne].
1s2 2s2 2p6 3s2 3p6 can be expressed as [Ar].
What happens in terms of energy sub-shells when forming ions?
The highest energy sub-shells lose or gain electrons.
What is ionic bonding?
The electrostatic attraction between positive and negative ions.
What is the result of ions attracting oppositely charged ions in all directions?
Giant ionic lattice
How are the melting and boiling points of ionic compounds explained?
High temperatures are required to provide the energy sufficient to overcome the strong electrostatic attraction between the ions.
What happens to the melting points for giant ionic lattices, when ionic charge increases?
Melting point increases as there is a stronger attraction between ions.
Are ionic compounds soluble?
some ionic compounds are soluble and they dissolve in polar solvents such as water. The ones that do not: have a high charge density (for example AI3+), so hard for the polar solvent to break down the lattice structure, and to surround each ion in solution.
What does solubility require?
The ionic lattice must be broken down. polar solvent (e.g. water molecule) must attract and surround each ions.
What does solubility (of ionic compounds) depend on?
The relative strengths of the attractions within the giant ionic lattice and the attractions between ions and water molecules.
When can ionic compounds conduct electricity?
Not in the solid state.
When molten or dissolved in water.
