How does adding an atom affect the position of existing atoms and lone pairs?

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth

What is calcium oxide+diphosphorus pentoxide--> calcium phosphate balanced

What is produced from neutralization of an acid and a base? a. hydronium ions b. citric acid c. salt and water