What is a scientific theory?

If a || b and e || f, what is the value of y ?

What is the correct term for living the most sustainable life you can within your current circumstances?

The chemical equation below shows the reaction of sodium (na) and chlorine (cl) to form sodium chloride (nacl). 2na + cl2 → 2nacl in this equation, which of the following is a reactant? i. sodium ii. chlorine iii. sodium chloride