A fern is a member of a group of approximately 12,000 species of vascular plants that reproduce via spores and have neither seeds nor flowers.They differ from mosses by being vascular (i.e. having water-conducting vessels). They have stems and leaves, like other vascular plants.ost ferns have what are called fiddleheads that expand into fronds, which are each delicately divided. Leptosporangiate ferns (sometimes called true ferns) are by far the largest group, but ferns as defined here (ferns sensu lato) include horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns.
The density of H 2 O at 39.8 Â°C is 0.992 g/mL. Solution. Raoult's Law can be used to express the vapor pressure relationships of solutions containing both volatile and nonvolatile solvents. Raoult's Law is expressed by. P solution = Ï solvent P 0 solvent where. P solution is the vapor pressure of the solution.
Guillaume Amontons (1663-1705) rediscovered the two basic laws of friction that had been discovered by Leonardo Da Vinci, and he also came up with an original set of theories. He believed that friction was predominately a result of the work done to lift one surface over the roughness of the other, or from the deforming or the wearing of the other surface.