Questions

A redox reaction is a type of reaction which involves transfer of electrons among two species. This reaction is also called oxidation-reduction reaction.

In oxidation process, there is an increase in oxidation state of an atom, ion or molecule by losing the electrons.

In reduction process, there is a decrease in oxidation state of an atom, ion or molecule by accepting the electrons.

1)

In this reaction, Ba undergoes oxidation and Cl undergoes reduction.
This reaction is redox reaction.
In this reaction, oxidation number of Ba increases from 0 to +2 . So, Ba undergoes oxidation. The oxidation number of Cl decreases from 0 to -1. So, Cl undergoes reduction.

2) 

From this above reaction, it is clear that Aluminum undergoes oxidation and silver undergoes reduction.
Due to this, this reaction is redox reaction.

In this reaction, oxidation number of Aluminum increases from 0 to +1. So, aluminum undergoes oxidation. The oxidation number of silver decreases from +1 to 0. So, silver undergoes reduction.

3)

In this reaction, Mg undergoes oxidation and Br undergoes reduction.
This reaction is redox reaction.
The reactions 1, 3 and 4 are redox reactions.
In this reaction, oxidation number of Mg increases from 0 to +2 . So, Mg undergoes oxidation. The oxidation number of Br decreases from 0 to -1 . So, Br undergoes reduction.

Hence all the above reactions are redox reactions.

There are nearly about 75000 enzymes of 3 classes are there in the human body. They are :

1. Metabolic Enzymes - Enzymes that help to run our Bodies

2. Digestive Enzymes - Enzymes that help in digesting Food

3. Food Enzymes - Enzymes from raw foods that start our Food digestion.

Nuclear Force

Mt. Etna

Memory refresh is the process of periodically reading information from an area of computer memory and immediately rewriting the read information to the same area without modification, for the purpose of preserving the information.

Memory refresh is a background maintenance process required during the operation of semiconductor dynamic random-access memory (DRAM), the most widely used type of computer memory.

Andhra Pradesh's TDP - Telugu Desam Party, today i.e on 16th March 2018 quit the NDA government at the Centre a week after two of its ministers resigned from the Union cabinet over the issue of special status for Andhra Pradesh.

S8 is an elemental form of sufur. In elemental form it can't be reduced or oxidized. Hence, it oxidation number is zero and thus sulfur is zerovalent here.