What type of reaction involves the formation of a new substance?

A chemical reaction is characterized by the transformation of reactants into products, resulting in the formation of one or more new substances with distinct chemical properties. During a chemical reaction, bonds between atoms break and reform, leading to this new arrangement of atoms, which constitutes a different substance altogether.

In contrast, physical reactions, such as phase changes, involve alterations in the state of matter (like melting or boiling) but do not create new substances at the molecular level. Similarly, while a neutralization reaction is a specific type of chemical reaction (involving an acid and a base), it is included under the broader category of chemical reactions, which encompasses all scenarios where new substances are formed.

Therefore, the correct answer highlights the general principle that defines a chemical reaction, making it distinct in its ability to yield new substances.