What is happening in a double replacement reaction

A double displacement reaction, also known as a double replacement reaction or metathesis reaction, is a type of reaction that occurs when the cations and anions switch between two reactants to form new products. ... A gas formation reaction is when two compounds react to form a gaseous product.

Explanation:

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >