What is the difference between a neutralization reaction and a double-displacement reaction? select one:
a. double/amp; ndash; displacement reactions are always redox reactions.
b. double/amp; ndash; displacement reactions always involve acids and bases.
c. neutralization reactions always produce water and a salt.
d. neutralization reactions are always combustion reactions?

I believe the correct answer is option C. The difference between a neutralization reaction and a double-displacement reaction would be that neutralization reactions always produce water and a salt. Double displacement reaction is a reaction that involves reaction of two compounds where the cations and the anions of the reactants would switch places producing new compounds. Neutralization reaction, on the other hand, always involve the reaction of an acid and a base forming a salt and water. Example  of a double displacement reaction would be 2BaCl + Na2SO4 = Ba2SO4 + 2NaCl. An example of a neutralization reaction would be HCl + NaOH = NaCl + H2O.

The density would be 1.622

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.