Bonds are broken and new bonds are formed during chemical reactions only.
Explanation:
A physical change in a substance doesn't change what the substance is.
In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
Physical changes can be reversed, chemical changes cannot be reversed with the substance changed back without extraordinary means, if at all. For example, a cup of water can be frozen when cooled and then can be returned to a liquid form when heated.
So, the right choice is:
Bonds are broken and new bonds are formed during chemical reactions only.
I've actually used the magnet test to determine if a gold necklace of mine was real or not. If the gold item aka the crown is attracted to a magnet, it is definitely not real gold.if it isn't then its real gold.
