Water is a vital substance for life on Earth, and it plays numerous important biological roles in living organisms. Some of the key biological roles of water are:

1. Universal solvent: Water is an excellent solvent for many substances, both organic and inorganic. This means that it can dissolve and transport a wide range of nutrients and minerals necessary for the growth and survival of living organisms.

2. Medium for metabolic reactions: Many metabolic reactions in living organisms require water...

Aksionov is the protagonist of the story "god sees the truth but waits" written by Leo Tolstoy. He is a young merchant. He is a handsome, fair-haired, curly-headed fellow, full of fun and very fond of singing. He used to drink much before marriage but later on, he changed himself and became a good man. He had virtuous qualities such as faith, forgiveness, freedom, and acceptance. His comfortable life is disrupted when he is framed for a murder he didn't commit and was sent to a...

II)Cr2+ is reducing agent as its configuration changes from d4 to d3, when it is oxidized to Cr3+ .The d3 configuration have a half-filled t2g level which is very stable. On the other hand, the reduction of Mn3+ to Mn2+ results in the half-filled (d5) configuration which has extra stability hence Mn3+ acts as oxidizing agent.