I think D?? I apologize if not-check in other answers to be sure ^^
Arrhenius theory is a theory about acids and bases. It says that acids are those substances that produces hydrogen ions (H+) when in solution and bases are the substances that dissiociates and produces hydroxide ions (OH-). It was introduced by Svante Arrhenius.
Explanation:
(1). It is known that in a reaction equation, reactants are placed or written on left hand side and products are written on the right hand side.
For example, 
Hence, in a reaction equation you start with the reactants and end up with the products.
(2). The number of atoms in a reaction will remain the same because according to the law of conservation of mass, mass of reactants will be equal to the mass of products.
Therefore, number of atoms on the reactant side will be equal to the number of atoms on product side.
B. a circle graph
circle graphs are the best to show percentages because they’re very easy to look at and get info from
Explanation:
The similarities between chemical and physical changes include change in state of matter and both process involve change in energy.
Chemical changes of a substance results in the formation of entirely new substances. These changes are not reversible.
Physical changes results in the change of the state of the substance which can be reversed.
However, both chemical and physical changes results in change of state of matter and both process results in change in energy.
Thus, we can conclude that the similarities between chemical and physical changes include change in state of matter and both process involve change in energy.
(it's alre answered but here it again 'NOTE: not my answer')
