ANSWER:
4 a) Specific elements have more than one oxidation state, demonstrating variable valency.
For example, the following transition metals demonstrate varied valence states:
,
,
, etc.
Normal metals such as
also show variable valencies. Certain non-metals are also found to show more than one valence state 
4 b) Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.
For example, Carbon-14 is a naturally occurring radioactive isotope of carbon, having six protons and eight neutrons in the nucleus. However, C-14 does not last forever and there will come a time when it loses its extra neutrons and becomes Carbon-12.
5 a)
→
5 b)
→ 
5 c)
→
(already balanced so don't need to change)
5 d)
→
5 e)
→ 
EXPLANATION (IF NEEDED):
1. Write out how many atoms of each element is on the left (reactant side) and right (product side) of the arrow.
2. Start multiplying each side accordingly to try to get atoms of the elements on both sides equal.
EXAMPLE OF BALANCING:
Answer:
When melted or dissolved in water.
Explanation:
Potassium bromide in its solid form contains ions, which are charged atoms. Through the heating process, the melted potassium bromide becomes an ionic liquid. If solid potassium bromide is dissolved, for example in water, the resulting release of ions allows it to conduct electricity.
Van der waals force
Explanation:
The intermoleclular forces are attraction between molecules. Interatomic forces are attraction between atoms in a compound.
In most hydrocarbons the weak Van der waals attraction are known.
- These forces are weak attraction joining non-polar and polar molecules together.
- These forces can also be found in layers of graphite.
- They are of two types;
London dispersion forces are attraction that exists between non-polar molecules and the noble gas.
Dipole - Dipole attractions are forces of attraction existing in polar molecules.
In hydrocarbons, we have non-polar molecules and intermolecular attraction is london dispersion forces.
learn more:
Intermolecular forces brainly.com/question/10107765
#learnwithBrainly
Ok the ML (the 3rd number) is not legit because the ML value can only be from -L to L (the second value)