Answer : The reagent present in excess and remains unreacted is, 
Solution : Given,
Moles of
= 3.00 mole
Moles of
= 2.00 mole
Excess reagent : It is defined as the reactants not completely used up in the reaction.
Limiting reagent : It is defined as the reactants completely used up in the reaction.
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,

From the balanced reaction we conclude that
As, 2 moles of
react with 1 mole of 
So, 3.00 moles of
react with
moles of 
From this we conclude that,
is an excess reagent because the given moles are greater than the required moles and
is a limiting reagent and it limits the formation of product.
Hence, the reagent present in excess and remains unreacted is, 
It's the balance of chemical equation.
Answer:
D number of protons or atomic mass
Answer:
option C= hydrolysis and break down
Explanation:
All other three pairs are correct coupling of each others.
Option A= dehydration synthesis and hydrolysis
Dehydration synthesis:
In dehydration synthesis monomers combine through the covalent bonds and form large molecules. The large molecules are called polymers. The water as a byproduct also released when monomers joints together.
Hydrolysis:
In hydrolysis the polymers are break down into monomers by using water molecules. The catalysts are also required in this process.
Option B= Catabolic and Anabolic
Anabolic:
In this process smaller molecules combine to gather to form large complex molecules by using energy.
For example simple glucose molecules join together to form large disaccharides.
Catabolic:
It is the break down of large complex molecules to the smaller molecules.
For example during cellular respiration sugar molecules break down and generate energy.
Option D= Break down and synthesis
The break down and synthesis are also reverse pair of each others. The synthesis involve the formation of molecules form smaller component while the break down involve destruction of molecules into smaller units.
The principal quantum number, <span>nn</span>, designates the principal electron shell. Because n describes the most probable distance of the electrons from the nucleus, the larger the number n is, the farther the electron is from the nucleus, the larger the size of the orbital, and the larger the atom is. n can be any positive integer starting at 1, as <span><span>n=1</span><span>n=1</span></span> designates the first principal shell (the innermost shell). The first principal shell is also called the ground state, or lowest energy state. This explains why <span>nn</span> can not be 0 or any negative integer, because there exists no atoms with zero or a negative amount of energy levels/principal shells. When an electron is in an excited state or it gains energy, it may jump to the second principle shell, where <span><span>n=2</span><span>n=2</span></span>. This is called absorption because the electron is "absorbing" photons, or energy. Known as emission, electrons can also "emit" energy as they jump to lower principle shells, where n decreases by whole numbers. As the energy of the electron increases, so does the principal quantum number, e.g., n = 3 indicates the third principal shell, n = 4 indicates the fourth principal shell, and so on.