It would be an physical change ; if you melt butter the butter goes from a solid to a liquid so therefore the physical state is changed.
Sorry, I won't understand your words.
Answer:
This is when two or more compounds or elements react to form a single product.
In these reactions new substances are produced or synthesized.
in simple terms the elements or compounds are converted to something new.
Grams. It is a smaller unit.
The mass of a chemical substance is known as the atomic number or atomic mass
