The home row refers to the row of keys on the keyboard where the fingers rest when one is not typing. The row is the reference point from which all the other keys can be reached and is usually the middle row on the keyboard.

The comparison of two numbers or quantities by division is known as the ratio. Symbol ‘:’ is used to denote ratio.

The kings claimed high status in ancient times by the following ways:—

1. Divine King- There were many rulers whose social origin were obscure, thus to raise their social status many like Kushanas began to portray themselves as divine. For example there is a statue of Kanishka in a temple and it is also displayed in te coins they produced. They also adopteped grandiose title like " Devaputra" or sons of god.

2. The rulers also tried to claimed higher status by deriving their revenuesfrom long distance trades. They just did not depend on agriculture but made ample use of the booming long distance trade to higher their status.

3. Some rulers like Guptas encircled themselves with the powerful samantas, the more powerful samantas were under the more higher status for the ruler. But samantas were also a kingmaker.

5. Other ways of claiming higher status were commisioning poet and other to write Prashastis about them, thus immortalising themselves through the words of poet.

When heat energy is supplied to ice it changes into water and then to vapor. If we cool the steam it gets converted into water and further cooling of water changes into ice.
Here the heat energy is used up in changing the state of matter. the heat is used to increase the kinetic energy of the particles of ice to such an extent that they break away from the rigid lattice structure of the solid form, ice, and move around freely to form the liquid form, water. So, until all the ice has melted, the heat absorbed does not raise the temperature of the ice-water mixture. In the same way the temperature does not change while a liquid is boiling. This heat, which does not raise the temperature of the body, is called Latent Heat.

49x² – 36
=(7x)² –(6)²
So from third identity, it can be written as
=(7x-6)( 7x+6)

The environment refers to our immediate surroundings in which all living and non-living components co-exist. It can be used to refer to the social, natural or built environment. The environment has a huge impact on an individual’s behaviour and intellect. Any change that occurs in a living entity either directly or indirectly is related to a change in his immediate surrounding.

There are two different types of environment:

• Geographical Environment
• Man-made Environment

Denaturation of Proteins

•   The most stable conformation of a protein at a given temperature and the pH is known as its native state.

•   The loss of biological activity of proteins when a protein in its native form, is subjected to physical change like change in temperature or chemical change like change in pH, is called denaturation of protein.

•   For example: (i) Coagulation of egg white on boiling, (ii) curdling of milk which is caused due to the formation of lactic acid by the lactobacillus bacteria present in milk.

Primitive Subsistence Farming: This type of farming is practiced on small patches of land. Primitive tools and family/community labour are used in this type of farming. The farming mainly depends on monsoon and natural fertility of soil. Crops are grown as per the suitability of the environmental condition.

This is also called <i>‘slash and burn’</i> agriculture. A patch of land is cleared by slashing the vegetation and then the slashed plants are burnt. The ash; thus obtained is mixed with the soil and crops are grown.

The term ‘aqua regia’ is Latin for ‘royal water’.

Aqua regia is a very strong acid formed by the combination of concentrated nitric acid and concentrated hydrochloric acid, both of which are strong acids.

It is generally used to remove metals like gold and platinum from substances, especially in microelectronics and micro-fabrications labs.

It is usually a yellow, reddish-orange, fuming liquid and has a rapidly changing composition.

It is primarily popular for its ability to dissolve gold, palladium and platinum, all of which dont react easily with chemicals.

The reason aqua regia can dissolve gold (and metals like platinum and palladium) is that each of its two component acids

(i.e., hydrochloric acid and nitric acid) carries out a different function. While nitric acid is an excellent oxidizing agent, the chloride ions from the HCl form coordination complexes with gold ions, thereby removing them from the solution.

The reduction of the concentration of Au³⁺ ions shifts the equilibrium towards the oxidized form.

The gold present in aqua regia dissolves completely to form chloroauric acid (HAuCl₄).

The striking surface of the matchbox contains red phosphorus and the head of the matchstick contains potassium chlorate. So when the matchstick is rubbed on the matchbox, some of the red phosphorus is converted to white phosphorus, a chemical i.e. so volatile that it ignites in air.

Metals react with water and produce metal oxides and hydrogen gas. The reaction depends upon the reactivity of metals.

Metals like potassium and sodium react violently with cold water. The reaction of calcium with water is less violent.

Magnesium does not react with cold water. It reacts with hot water to form magnesium hydroxide and hydrogen.

Metals like aluminium, iron and zinc do not react either with cold or hot water.

But they react with steam to form the metal oxide and hydrogen. Metals such as lead, copper, silver and gold do not react with water at all.

Non-metals do not displace hydrogen because they form negative ions by accepting electrons while hydrogen like metals forms a positive ion.

Therefore metals can displace hydrogen while non-metals cannot.

Highly reactive metals like Sodium reacts with dilute hydrochloric acid according to the following equation:

2Na (s) + 2HCl (aq) → 2NaCl (aq) + H₂ (g)

Hydrogen bubbles will be forming in the solution.

Writing in ionic form:-

2Na (s) + 2H⁺¹ (aq) + 2Cl^-1 (aq) → 2Na⁺¹ (aq) + 2Cl^-1 (aq) + H₂ (g)

Both the sodium atoms are neutral.

But hydrogen on the reactants side has +1 charge whereas in product side it is neutral.

Therefore Na donates one electron to each of hydrogen ion.

Less reactive metals like Zinc reacts with dilute acids.

Zn (s) + 2HCl (aq) → ZnCl₂ (aq) + H₂ (g)
It doesnt matter which metal or which acid is used, if there is a reaction we always get hydrogen gas as well as the salt.

However, how quickly the reaction goes depends on the metal used and how high up in the reactivity series it is.

The term ‘aqua regia’ is Latin for ‘royal water’.

Aqua regia is a very strong acid formed by the combination of concentrated nitric acid and concentrated hydrochloric acid, both of which are strong acids.

It is generally used to remove metals like gold and platinum from substances, especially in microelectronics and micro-fabrications labs.

It is usually a yellow, reddish-orange, fuming liquid and has a rapidly changing composition.

It is primarily popular for its ability to dissolve gold, palladium and platinum, all of which dont react easily with chemicals.

The reason aqua regia can dissolve gold (and metals like platinum and palladium) is that each of its two component acids

(i.e., hydrochloric acid and nitric acid) carries out a different function. While nitric acid is an excellent oxidizing agent, the chloride ions from the HCl form coordination complexes with gold ions, thereby removing them from the solution.

The reduction of the concentration of Au³⁺ ions shifts the equilibrium towards the oxidized form.

4p² – 9q²
=(2p)² –(3q)²
So from third identity, it can be written as a² –b² = (a-b)(a+b)
=(2p-3q)( 2p+3q)

नेता जी की आँखों पर चश्मा नहीं था . यानी चश्मा तो था किन्तु चश्मा संगमरमर का नहीं था . एक सामान्य के चश्मे का चौड़ा काल फ्रेम को पहना दिया था . हालदार साहब को यह तरीका पसंद आया 

Bleaching powder is needed in the manufacture of chloroform. Bleaching powder (CaOCl2​) supplies the necessary chlorine and slaked lime (calcium hydroxide).

CaOCl₂​+H_2​O→Ca(OH)_2​+Cl₂​

A paste of bleaching powder in water is distilled with ethanol or acetone to obtain chloroform.

Carbon tetrachloride, also known as tetrachloromethane, is an organic compound with the chemical formula CCl4. This compound is often classified as a polyhalogenated organic compound since it consists of a carbon atom which is attached to more than one halide functional group.

Adaptive features of a lion that helps it in hunting are as follows: 
1. A lion has slight brown body, which helps it to hide itself in dry grassland for avoiding detection by its prey.
2. Detects its prey from a distance and knows the exact location of it because of its own eyes located in front.
3. Strong paws, sharp teeth and long claws help it to catch and kill the prey.

Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer (VCM), as shown.<a href="https://en.wikipedia.org/wiki/File:Vinyl_chloride_Polymerization_V1.svg" title="The polymerisation of vinyl chloride"></a>

Hydrolysis is a common form of a chemical reaction where water is mostly used to break down the chemical bonds that exists between a particular substance.

The general formula of a hydrolysis reaction is:

AB+H₂O→AH+BOH

Radical

    Radical is an atom or a group of atoms of same or different elements which behaves like a single atom with a positive or a negative charge on it. 

    Radicals have their own combining power based on which they form chemical formulae. 

 Example: 

    NH₄⁺, Na⁺, NO₃⁻, SO₄²⁻ 

The full form of TNT is Trinitrotoluene. TNT is a yellow solid that is often seen as a reagent in the chemical synthesis process but is commonly known for being an explosive substance with smooth handling characteristics.

Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution. When copper reacts with the elements (oxygen, water and carbon dioxide), it turns from its element color of reddish-brown to green. This chemical reaction is hydrated copper carbonate, and a famous example of it is the Statue of Liberty.

The endocrine glands release hormones into bloodstream to reach a particular body part called target site. The target site responds to the hormone. the particular site where the hormones reach through the bloodstream is called the target site.

Improves concentration power, correct body posture, Rehabilitation of injuries, Increases flexibility, Improves breathing system, Improves function of heart, Improves digestive system, Improve overall health, Improves coordination of function between neurology and muscles.

4+812-05

= 816 - 5

= 811

Pbs(s) + 4H₂O₂(aq) → PbSO₄(S) + 4H₂O(I)