Answer: burning paper
Explanation:
The paper burns in air to form smoke and ash. which makes it a chemical change.
A scale and a ruler. The scale to measure the mass, and a ruler to measure the volume.
Avogadro’s number allows you to change moles to number of molecules/atoms.
The number of neutrons in a nucleus affects the mass of the atom but not its chemical properties. Thus, a nucleus with six protons and six neutrons will have the same chemical properties as a nucleus with six protons and eight neutrons, although the two masses will be different.