• The elements in which the last electron enters the outermost s-orbital are called s-block elements. s-block has two groups (1 and 2).
• Group 1 elements are called alkali metals. They form hydroxides by reacting with water that is strongly alkaline in nature and hence are regarded as alkali metals.
• Whereas Group 2 elements are called alkaline earth metals. The oxides and hydroxides of these metals are alkaline in nature and exist in earth crust and hence are regarded as alkaline earth metals.

Rules:

• Oxidation number of free element is always ZERO
• Example: The oxidation number of atoms in O₂, H₂ and N₂ = 0
• The oxidation number of Hydrogen is +1
• Exception: In Metal hydrides the oxidation state of hydrogen is -1
• The Oxidation state of IA group elements = +1
• The oxidation state of IIA group elements = +2
• The oxidation number of IIIA group elements = +3
• The oxidation state of Oxygen = -2
• Exception: The Peroxides and super oxides the oxidation state is -1, -1/2 respectively
• The oxidation state of VIIA group elements = -1
• Exception: In inter halides the oxidation state will differs
• In neutral compound the sum of oxidation numbers of all the atoms = 0
• In polyatomic ions the sum of the oxidation number is equal to charge on the ion
• Example: Hydroxide ion (OH-) the oxidation number = -1

{tex}\begin{array}{l}\frac d{dx}(\;(2x+3)(3x-5)=(3x-5)\frac{\displaystyle d}{\displaystyle dx}(2x+3)\;+(2x+3)\frac{\displaystyle d}{\displaystyle dx}(3x-5)\\(3x-5)(2)+(2x+3)(3)\\=6x-10+6x+9\\=12x-1\end{array}{/tex}

Two way purpose is served by wholesalers providing warehousing facilities in the following manner
(i) Wholesalers take delivery of goods when these are produced in factory and keep them in their godowns/warehouses which reduces the burden of manufacturers of providing for storage facilities for the finished products.
(ii) Warehousing by wholesalers relieves the retailers of the work of collecting goods from several producers and keeping big inventory of the same for maintaining adequate stock of varied commodities for the customers.

A departmental store is a large establishment offering a wide variety of products, classified into well-defined departments, aimed at satisfying practically every customer’s need under one roof. It has a number of departments, each one confining its activities to one kind of product, e.g., there may be separate departments for toiletries, medicines, furniture, groceries, electronics, clothing and dress material. Thus, they satisfy diverse market segments with a wide variety of goods and services.
Some of the important features of a departmental store are as follows
(i) A modem departmental store may provide all facilities such as restaurant, restrooms, etc. In this way they try to provide maximum service to higher class of customers for whom price is of secondary importance.
(ii) These stores are generally located at a central place in the city, which caters to a large number of customers.
(iii) They are generally formed as a joint stock company managed by a board of directors as the size
of these stores is very large.
(iv) A departmental store combines both the functions of retailing as well as warehousing. They purchase directly from manufacturers and operate separate warehouses thereby eliminating undesirable middlemen between the producers and the customers.
Chain stores or multiple shops are networks of retail shops that are owned and operated by manufacturers or intermediaries. Under this type of arrangement, a number of shops with similar appearance are established in localities, spread over different parts of the country in contrast to departmental stores which are established at a central place in the city. These different types of shops normally deal in standardized and branded consumer products, which have rapid sales . turnover. These shops are run by the same organisation and have identical merchandising strategies, with identical products and displays

TriCarboxylic Acid (TCA) cycle. 

In prokaryotic cells, the citric acid cycle occurs in the cytoplasm; in eukaryotic cells, the citric acid cycle takes place in the matrix of the mitochondria. 

The cycle was first elucidated by scientist “Sir Hans Adolf Krebs” (1900 to 1981). He shared the Nobel Prize for physiology and Medicine in 1953 with Fritz Albert Lipmann, the father of ATP cycle.

The process oxidises glucose derivatives, fatty acids and amino acids to carbon dioxide (CO2) through a series of enzyme controlled steps. The purpose of the Krebs Cycle is to collect (eight) high-energy electrons from these fuels by oxidising them, which are transported by activated carriers NADH and FADH2 to the electron transport chain. The Krebs Cycle is also the source for the precursors of many other molecules, and is therefore an amphibolic pathway (meaning it is both anabolic and catabolic)

This may help you.