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.
One difference is that some animals are polyp and some are medusa.
The other difference is that some animals have medusa in their life or polp in their life cycle.
Hope these two differences helps :D
A metalloid is a metal and a nonmetal
Compound can be described using element symbol and numbers . it is a mixture which is result of two or more chemical element in such a way that atoms of different elements held together by chemical compound that are difficult to break . Most often a compound looks and behave like an element
for example :- Hydrogen and oxygen .. both of these elements are gaseous at room temperature and atmospheric pressure , but when both combined they both form compound water . ( H2O )
