False, the chemical make up hardly ever changes, The physical property is the one that changes
It helps us know the genetics of genes.
<span>It is a nerve agent. Or chemical asphyxiant. An example is Hydrogine Cyanide. </span>
The answer is option B "declining number and variety of the species in an area." Biodiversity is a variety of life for example a ecosystem has many species which makes it a biodiversity. Now a loss of a biodiversity would be loosing a huge amount of species in that area or ecosystem which would mean the answer is option B.
Hope this helps.