Answer:
            Ionic bond is formed by the opposite ions attraction between the 2 atoms in an ionically bonded compound. The two ions i.e. Cation and Anions are formed by oxidation and reduction reactions respectively. General Ionic formula is as follow,
                                             Mⁿ⁺ + Nⁿ⁻   →  MN
where;
           Mⁿ⁺   =  Cation
           Nⁿ⁻   =  Anion
           MN  =  Salt
Explanation:
                   Ionic bond is the electrostatic forces of attraction between positively charged cations and negatively charged Anions. These forces are very stronger resulting in increasing several physical properties of Ionic compounds like melting point and boiling point e.t.c.
Example:
Sodium Chloride:
                           NaCl is formed by Na⁺ cation and Cl⁻ anion as follow,
Oxidation of Na;
                                      2 Na  →  2 Na⁺  +  2 e⁻
Reduction of Cl₂;
                                    Cl₂  +  2 e⁻  →  2 Cl⁻
Crystal Lattice formation is as follow,
                                  Na⁺  +  Cl⁻   →  NaCl
        
             
        
        
        
Answer:
c.- How much of the reactants are needed and how much product will made. 
Explanation:
The moles is the matter unit used in chemistry to simplify  some calculations, instead of using grams. Also the moles are very useful because the chemical reaction can be balanced. 
When a Chemical reaction is balanced, then it can be easily to calculate how many moles are necessary to add in a process to obtain a quantity of grams of a product. 
 
        
             
        
        
        
Answer:
YES YES YES YES YES YES YES YES YES YES YES YES
 
        
                    
             
        
        
        
D. How the pull of gravity has changed.
        
             
        
        
        
Answer:

Explanation:
Hello there!
In this case, for the reaction by which water is decomposed to molecular hydrogen and oxygen:

It is necessary to perform the inspection balance process since there is a dissimilar number of atoms of oxygen on both sides; therefore, by putting a 2 on water we balance oxygen:

But now, there are four hydrogens on the left; therefore, we put a 2 on hydrogen to finally balance it:

And obviously, the coefficient in oxygen is an unwritten 1.
Best regards!