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.

There are eight protons in an Oxygen's nucleus.
Answer:
B
Explanation:
Step 1 occurs at a slower rate than Step 2.
Answer:
See explanation
Explanation:
A. Constitutional or structural isomers have the same molecular formula but different structural formulas.
B. Conformational isomers are compounds having the same atom to atom connectivity but differ by rotation about one or more single bonds.
C. Stereo isomers are compounds having the same molecular mass and atom to atom connectivity but different arrangement of atoms and groups in space.
I. Enantiomers are stereo isomers (optical isomers particularly) that are non-superimposable mirror images of each other.
II. Diasteromers are optical isomers that are not mirror images of each other.
Both diasteromers and enantiomers are types of optical isomers which in turn is one of the types of stereo isomers.
Stereo isomers differ from conformational isomers in that the arrangement of atoms in stereo isomers is permanent while conformational isomers results from free rotations in molecules about single bonds.