Questions

Hence, soil erosion on hillslopes can be checked by Terrace cultivation.

The given compound is NaHCO3 Sodium bicarbonate which is commonly known as Baking soda.

Oxidation numbers are the charges on ions. When a neutral atom loses electrons it becomes positively charged. When a neutral atom gains electrons it becomes negatively charged.

Here the C represents the oxidation state of carbon in this compound. Compounds are electrically neutral, which is why we set the sum of the oxidation states equal to zero.

Sodium has a +1 oxidation state. Hydrogen has a +1 oxidation state. Oxygen has a -2 oxidation state. There are three oxygen atoms, which means the total oxidation state provided by both oxygen ions is -6. Adding up these oxidation states we get:

1 + 1 + (-6) + C = 0

-4 + C = 0

=> C = 4

This means the oxidation state of carbon in this compound is +4.

Plants receive their nutrients mainly from Soil.

Because Soil contains all Minerals, Water, Humus and some useful Microbes which are responsible for the proper Growth of the Plants.

In word, the mailing list is known as the Data source.

Gross domestic product (GDP) is the monetary value of all the finished goods and services produced within a country's borders in a specific time period.

Simply, GDP is a broad measurement of a nation’s overall economic activity. 

It is calculated by summation of Consumption, investment, government purchases, and net exports.