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Vineeta Jeena 8 years ago

First group of periodic table
  • 1 answers

Tanuja Jangir 8 years ago

A mole is the amount of a substance.The mole is the base unit of international system of units.
  • 1 answers

Farhan Af 8 years ago

Because small size,high deplorizing charge,absence of vacant d orbital
  • 1 answers

Ganesh Singh 8 years ago

When H react with active to form binary compound is known hydrides
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Nishi Maurya 8 years ago

Combination of two or more compounds or elements to form another substance

Rishab Kumar 8 years ago

Combination in elemets or compound.
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Amar Kumar 8 years ago

The cathode ray tube is a vacuum tube that contains one or more electron guns and a phosphorescent screen, and is used to display images. It modulates, accelerates, and deflects electron beam onto the screen to create the images.

A cathode ray tube (CRT) is a specialized vacuumtube in which images are produced when an electron beam strikes aphosphorescent surface. Most desktop computer displays make useof CRTs. The CRT in a computer display is similar to the picture tube in a television receiver.

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Amar Kumar 8 years ago

Heisenberg's indeterminacy principle:It states that the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa.

Heisenberg's Uncertainty Principle states that there is inherent uncertainty in the act of measuring a variable of a particle. Commonly applied to the position and momentum of a particle, the principle states that the more precisely the position is known the more uncertain the momentum is and vice versa.

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Vineeta Jeena 8 years ago

118

Himanshu Sharma 8 years ago

118

A Z 8 years ago

There are 118 elements in modern periodic table.

Ranbir Trikha 8 years ago

118
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Bharti Sinha 8 years ago

It is a process in which we mix orbital as such that their nature become uniform i. e. their energy should be equal

A Z 8 years ago

Hybridisation occurs when 2 or more atomic orbitals mix to form new atomic orbitals.
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Yash Batham 8 years, 1 month ago

Chal bhagg
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Amar Kumar 8 years, 1 month ago

Hydrogenation is a reduction reaction which results in an addition of hydrogen H2. If an organic compound is hydrogenated, it becomes more saturated.

Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds.

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Amar Kumar 8 years, 1 month ago

Elimination reaction :It is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism.[2] The one-step mechanism is known as the E2 reaction, and the two-step mechanism is known as the E1 reaction.

Examples of E2 Reactions: All E2 reactions have two things in common: a good leaving group and a hydrogen atom on a carbon adjacent to the one with the leaving group. Alkyl halides and alcohols are the most common reactants in an E2 reaction. 

Alkyl halides undergo elimination to produce alkenes. E2 elimination from RX Alcohols undergo elimination to produce alkenes. E2 ROH Notice that E2 elimination of an alcohol uses acid, not base. In mechanism, the acid is used to make the -OH group into a better leaving group, which is water. The E2 Mechanism Here we see the mechanism of E2 elimination from an alkyl halide, RX. Bimolecular elimination occurs in a single, concerted step.

E2 mechanism :This reaction works best when the halide is primary or secondary. As noted earlier, a base takes a proton (H+) from a carbon adjacent to the one with the X. The electrons that had formed the C-H bond are now used to make a new C-C pi bond. When the new bond forms, the leaving group leaves with its electron pair. Elimination of water from a primary alcohol is possible, but difficult. However, if it occurs it will use the E2 mechanism. Unimolecular elimination reactions, also called E1, use a different mechanism that involves a carbocation. Since primary carbocations rarely form, elimination of a primary alcohol will occur via E2 .

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Akash Singh 8 years, 1 month ago

Because every body has a tendency to obtain lesser surface area and sphere has the least surface area so it tends to be sherical in shape.
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Vaishnavi Sharma 8 years, 1 month ago

There are two vanderwaal constants 'a' and 'b' . a stands for magnitude of attractive forces and b stands for excuded volume or Co volume . Unit of a is atm L2 mol-2 Unit of b is L mol-1

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