A substance either an ion or a molecule that can act either an acid or a base depending on a medium is called Amphoteric. Some metals like zinc, tin, copper and aluminium which produce either metal oxides or hydroxides are examples of amphoteric. During the Amphoterism, the metal compound acts either an acid or a base depending on their oxidation state.
I think A but I’m not sure so
Explanation:
A chemical reaction is one in which a chemical change occurs.
During a chemical change;
- The process is irreversible
- New kinds of matter produced
- There is a change in mass
Based on these premise;
Baking cake batter is a chemical reaction because you cannot reverse the process
Shredding a paper is not a chemical reaction because no new kind of matter is produced.
Twisting of a metal wire is not a chemical reaction
Yellowing of newspaper in sunlight is a chemical change. The process cannot be reversed