What is the term for rearranging atoms in a molecule so that the product has the same chemical formula but a different structure?

The term that describes the rearrangement of atoms in a molecule, resulting in a product that maintains the same chemical formula but adopts a different structure, is isomerization. This process involves changing the connectivity of atoms within a molecule, leading to the formation of isomers. Isomers are compounds that share the same molecular formula but differ in the arrangement of atoms, which can significantly impact their chemical properties and reactivity.

For instance, isomerization can occur in hydrocarbons where the carbon skeleton is rearranged while the number of carbon and hydrogen atoms remains unchanged. This is especially important in refining processes, as different isomers can have distinct physical properties that may be advantageous for specific applications, such as fuel or chemical production.

The other options listed refer to different chemical processes. Hydrotreating involves adding hydrogen to reduce or remove impurities, hydrocracking is a method used to break down larger hydrocarbons into smaller, more valuable products, and fluid catalytic cracking is a technology for converting heavy hydrocarbon fractions into gasoline and other lighter hydrocarbons by using a catalyst. Each of these processes focuses on altering the composition or weight of hydrocarbon mixtures rather than simply rearranging atoms within a single molecule.