The answer is (2) Copper. Because copper is consist of atom. If it is decomposed, the atom will be changed. While chemical change is just the break down and form of chemical bonds between atoms.
The astronomical unit or also know as AU. Scientists use this because it’s convenient and easier to understand! Hope this helps ;)
Answer: 6.02214076 atoms Ca
Explanation:
Ca is monoatomic, so atoms in 1 mol = avogadro number
