Answer: 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here iron is having an oxidation state of +3 called as
cation and oxide
is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral
.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Mostly in my opinion I think it’s the secound one
Answer:
A
Explanation:
add 22 with the answers like A, 33+22=55
Answer:
the maximum extent of a vibration or oscillation, measured from the position of equilibrium.
Explanation:physics
Hello! The answer is D
A good note for these is when there are three elements, one being a singular element and another a compound and there’s a single switch, this could show a single-displacement
Have a good day gamer.