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Important 500 Questions Of Chemistry-1
Which particles are present in the nucleus of an atom – proton and neutron
The scientist who discovered ‘Atomic Theory’ – John Dalton
What is the charge on an electron-1.6 x 10-19C
Atoms are electrically neutral
Electron was discovered by – Thomson
Who discovered proton – Goldstein
An Indian scientist whose name is associated with a specific fundamental particle – Bose
Neutron was discovered by – Chadwick
The chemical behavior of an atom depends on the number of electrons revolving around its nucleus.
The total energy of an electron revolving in an atom is always positive.
The international standard of atomic weight is – C-12
The half-life of a radioactive substance is 4 months. It will take time for three-fourth of this substance to decay – 8 months
Earth’s age is estimated through uranium dating.
What is determined by radio carbon dating – age of fossil
Who invented the atomic bomb – Otto Hahn
On what principle does a nuclear power plant work – Fission
Which type of reaction produces the most harmful radiation – Fission reaction
Energy is emitted from the Sun – through nuclear fusion
Which substance works as a moderator in a nuclear reactor – heavy water
The process of fission is responsible for releasing energy in the atomic bomb.
Cobalt-60 is commonly used in radiation therapy because it emits – gamma rays.
On what principle does the hydrogen bomb work – uncontrolled fusion reaction
The half-life of a radioactive substance is 10 days. This means that 3/4th of the substance will be decomposed in 20 days.
A radioactive element of which large reserves are found in India – Thorium
The fuel in Kalpakkam’s fast breeder reactor is – enriched uranium.
Carbon dating is used to determine the age of – fossil
The difference between isotopes of an element is due to the presence of different numbers of – neutrons
An isotope of an atomic nucleus is a nucleus that has the same number of protons, but a different number of neutrons.
Radioactive isotope of hydrogen is called – Tritium
What is the number of isotopes of hydrogen – 3
The largest number of isotopes are found in – Polonium
The number of isotopes of polonium is – 27
Isotones have – equal number of neutrons
Those ions which have the same number of electrons are called – isoelectronic
By whose emission areosceles are produced – beta rays
Cobalt-60 is commonly used in radiation therapy for diseases like cancer, because it emits – gamma rays.
Which radioisotope is used to control blood cancer (leukemia) – Cobalt-60
Acid is a substance which gives protons.
What are the main pollutants of cigarette smoke – carbon monoxide and benzene
In what form do plants take nitrogen – Nitrates
If the plants found on Earth disappear, then which gas will be in shortage – Oxygen
What is used to test acid and ash – litmus paper
What is water soluble base called – Alkali
Who determined the pH value – Sorensen
What do all acids provide when dissolved in water – H+ ions
Cow dung gas mainly contains – methane
L.P.G. Which gas is mainly present in (P.G.) – Butane
What is the full name of G. – Liquefied Petroleum Gas
Why is G. called eco-friendly – it has very less carbon monoxide
Which fuel produces minimum environmental pollution – Hydrogen
The fuel used to run a rocket is called – Propellant
Among the different varieties of coal, the percentage of carbon is the highest – Anthracite
Brown coal is known as – Lignite.
What type of fire extinguisher is used for petrol fire – Foam type
Which gas is used in fire fighting – CO2
Which is the best fuel in terms of energy released per gram of fuel – Hydrogen
Producer gas is a mixture of – CO+N2
Which can be used as propellant or fuel in rockets – Liquid Hydrogen + Liquid Oxygen
Who discovered the catalyst – Berzelium
Catalytic poison is – action inhibitory
Bio-Catalyst is – Enzyme
The catalyst used in hydrogenation of oils is – Ni
Oxides of nitrogen are used as catalysts in the chamber process.
Which enzyme converts glucose into alcohol – Zymase
The heaviest metal is – Osmium
The lightest metal is – Lithium
The lightest element is- hydrogen
The element found in greatest quantity on Earth is – Oxygen.
Which is a man-made element – California
Nowadays, yellow lamps are being used extensively in street lighting. What is used in these lamps – Sodium
The chemical formula of caustic soda is – NaOH
The chemical formula of baking soda is – NaHCO3
Common salt is- sodium chloride
Who has the maximum contribution in the salinity of sea water – Sodium chloride
What is table salt made from – strong acid and strong base
The chemical name of baking soda is – sodium bicarbonate.
The chemical used as a stabilizer in photography is – Sodium thiosulphate.
‘Milk of Magnesia’ is a suspension of magnesium hydroxide.
Which main raw material is used in the manufacture of rayon – Cellulose
The reason for the sweet taste of fruits is – Fructose
Carbohydrate is the compound of – carbon, oxygen and hydrogen
Drying oils contain large amounts of unsaturated fatty acids.
Methylated spirit contains only methanol, is the statement correct – No
By which reaction can amides be converted into amines – Hoffman
Glycogen, starch and cellulose are polymers of – Glucose
The metallic component of chlorophyll is – Magnesium Glass is – An elastic solid
To provide hardness to steel, the amount of chromium is added.
Which material is most elastic – Steel
There is a coating on galvanized iron – zinc
Which process is not beneficial in preventing rusting of ore – Annealing
By applying which substance the bleeding from the cut site stops – Ferric chloride
Which metal was used by humans for the first time – Copper
The maximum permitted concentration of copper in drinking water in mg/L is – 2.0
When kept in air for some time, a layer of green colored basic carbonate forms on any metal. That metal is – copper
The best conductor of electricity is – Copper
While making gold jewellery, which metal is added to it – Copper
Slightly blue – copper sulphate
The gas used in cooking is mainly – methane
Most explosions in mines occur due to the mixture of methane with air.
LPG is a mixture of – butane and propane
Which gas was used as a chemical weapon in the First World War – Mustard gas
Why diesel is used in heavy vehicles – high efficiency and economic savings
Indane gas is a mixture of butane and propane.
Commercial Vaseline is extracted from – Petroleum
Paraffin is a by-product of petroleum refining.
What is the main component of petrol – Octane
Gasohol, which is used as fuel in motor vehicles, is a mixture of petrol and alcohol.
The wax obtained from petroleum is – Paraffin wax
In which only one type of atom is found – natural element
What is air – mixture
Ammonia is a chemical compound.
Diamond is – Element
Water is a compound because it consists of two different elements joined by chemical bonds.
Mixture is formed by mixing two or more pure substances in any ratio.
Such elements which have properties of both metals and non-metals are called metalloids.
Bleaching powder is – compound
Gunpowder is – mixture
Which gas is used in welding metal – Acetylene
Refrigerant is Freon – Difluoro dichloro methane.