One gram of pure gold would contain lots of gold a. atoms. b. elements. c. molecules. d. compounds.

Option (A) is the correct answer.

Explanation:

It is known that an element contains same type of atoms and it cannot be broken down into simpler substances.

For example, gold is an element which contains only atoms of gold.

A molecule is defined as the substance which contains same type of elements in fixed ratio by mass.

For example, is a molecule.

Whereas a compound is defined as the substance which contains different type of elements that are chemically combined together in a fixed ratio by mass.

For example, is a compound.

Thus, we can conclude that one gram of pure gold would contain lots of gold atoms.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

58750.08068 is the answer i think