Does the biosphere have clear boundaries

No, the biosphere does not exhibit a clear boundary as life always comes to an end.  

The biosphere comprises all the living things of the world, like all the plants and animals. It is considered as the global ecosystem, that is, the gathering of all the planet's ecosystems. It comprises the land and the atmosphere. It is usually considered as the zone of life, where all the species of the planet thrives.  

2b2t

explanation:

2b2t

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.