At the base of a nail, keratinized skin called the cuticle is also called the

The stratum corneum, the fifth, outermost layer is thick with rows of dead cells. These cells contain soft keratin, which keeps the skin elastic and protects underlying cells from drying out. The dermis, called "true skin, " is the layer beneath the epidermis

A  reaction  in which  energy  is  released  to the surroundings is called an exothermic  reaction. in this type of  reaction  the enthalpy, or stored  chemical energy, is lower for the products than the reactants. when ammonium nitrate is dissolved in water,  energyis  absorbed  and the water cools.