Which statement is true about a polyatomic ion? it forms metallic bonds with other ions. it forms covalent bonds with other ions. it is made of atoms that are covalently bonded together. it has a charge that is distributed over part of the entire unit

It is made of atoms that are covalently bonded together. It is also  called a molecular ion. Example are NH4+ and NO3--.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e