Either is fine. It depends on the situation.
------
Re is the chemical symbol of rhenium.
Ratooning of sugar cane is re-cultivation. Likewise other fodder crops such as Berseem, oat etc are re-cultivated after each cutting.
These particles are protons and neutrons; but to be correct the mass of electrons must be added.
It is "re" 👍
A chemical reaction in which the products re-form the original reactants is called a reversible reaction.
No.
re-implement
re-assign
it is re assign
Rethink
I dont't know a pyramid of Ra (Re is not so correct).
re-energize
Ra (Re is not so correct) is the ancient Egyptian god of the sun.
Create as always. Re can be re or rii. I don't think there is a distinction in meaning; it depends on your accent.
Resent is the correct spelling.
Reopen.
re-emergence
That is the correct spelling, "grand re-opening." It is only occasionally hyphenated re-opening.