Answer the following question given this paragraph: 

Even compounds with the same number of carbon and hydrogen atoms can have different shapes. These compounds are called isomers . Look at the examples in Figure below . The figure shows the structural formulas of butane and its isomer iso -butane. Both molecules have four carbon atoms and ten hydrogen atoms (C 4 H 10 ), but the atoms are arranged differently. Butane is a straight-chain molecule. Iso -butane is branched. You can see three-dimensional models of these two isomers at the URLs below. You can rotate the molecule models to get a better idea of their shapes.


Q: What are compounds with the same number of carbon and hydrogen atoms called?


A:
isomers