Why do electrons in lower energy levels have less energy than electrons in higher energy levels?
Electrons closer to the nucleus are strongly attracted due to strong electrostatic forces of attraction, so they are tightly bound, stable, and have low energy.
Electrons in higher energy levels are farther away, feel weaker attraction, are less stable, and have more energy because it takes work to move them from lower levels
What is n?
The Principle Quantum Number
n
Shell / energy level number
What are the subshells called?
S (sharp)
P (principle)
D (diffuse)
F (fundamental)
How many orbitals can fit into a subshell at maximum?
S - 1
P - 3
D - 5
F - 7
What is an orbital?
A region around the nucleus that can accommodate up to two electrons with opposite spins.
Also known as a region where an electron is most likely to be found inside an atom.
Why must electrons in the same orbital have opposite spins?
To satisfy Pauli’s rule, where no two electrons in the same atom can have the same four quantum numbers.
To also minimise electron repulsion.
What are two characteristics of orbitals?
Orbitals within the same sub-shell are of equal energy.
Each orbital can hold two electrons, which must have opposite spins (called spin-pairing).
What is the equation for the number of electrons found per n?
2n^2
Describe subshell S (sharp)?
Spherical in shape.
Found in every energy level, where n = 1 only has S.
There is one S orbital per shell
Describe subshell P (principle)?
Dumbbell shape.
Each shell from n = 2 has a P orbital.
There are three P orbitals per shell.
The three P orbitals are orientated at right angles to each other.
4s or 3d gets filled first?
4s as it has lower energy than 3d.
Where is D and F found?
D: n = 3
F: n = 4
How are d-block elements drawn using a box diagram?
4s comes before 3d in the box diagram.
How are d-block elements configured during electron configuration?
3d comes before 4s during electron configuration so that it becomes clear what electrons get lost first in the case of ions.
What happens in ionic bonding?
The metal loses its outermost electron(s) and transfers its electron(s) to the non metal so that they can both achieve a full outer energy level.
What is an ionic bond?
An ionic bond is the electrostatic force of attraction between oppositely charged ions, usually a metal and a non-metal.
These bonds are very strong.
When ions bond this way, an ionic compound is formed.
What is a giant ionic lattice?
Ions attract oppositely charged ions from all directions.
Why do ionic compounds have high melting and boiling points?
Because of the strong electrostatic forces of attraction between the oppositely charged ions that require a large quantity of energy to overcome.
Why are the melting and boiling points higher for larger ions?
There are stronger forces of attraction between the ions.
Why are ionic compounds soluble?
Ion compounds are polar, as well as water, so they are attracted to eachother.
The polar water molecules break down the lattice and surround their respective ions in solution.
Why are some larger ionic compounds not as soluble?
The ionic attraction may be too strong for the water to break down the lattice structure.
Why don’t ionic compounds conduct when solid, yet do when molten or aqueous?
The ions cannot move when solid, but they can move and carry an electric charge when molten or aqueous.
What is a covalent bond?
A covalent bond is the strong electrostatic attraction formed between a shared pair of electrons and the nuclei of the bonded atoms.
What is the attraction like for covalent bonds in comparison to ionic bonds?
The electrostatic attraction is localised/directional, acting solely between the shared pair of electrons and the nuclei of the bonded atoms.
