A chemical formula contains information on the types and spatial arrangement of bonds in the chemical. It also tells you what elements are in the chemical, and how many atoms of each. The spatial arrangement is not necessarily very obvious from the formula, e.g. C2H5OH does not tell you much about the spatial arrangement of the bonds. A chemical formula contains information on the types and spatial arrangement of bonds in the chemical.
All modern amphibians are included in the subclass Lissamphibia, which is usually considered a clade, a group of species that have evolved from a common ancestor. The three modern orders are Anura (the frogs and toads), Caudata (or Urodela, the salamanders), and Gymnophiona (or Apoda, the caecilians).
The groups of amphibians that survived to the present day can be traced back no further than 200 million years. Characteristics Amphibians are cold-blooded animals, meaning they do not have a constant body temperature but instead take on the temperature of their environment. They have moist, scaleless skin that absorbs water and oxygen, but that also makes them vulnerable to dehydration (loss of bodily fluids).