General Science Questions (MCQs) for Competitive Examinations
General Science Multiple choice questions for GK paper in SSC,OSSSC ,OSSC, NDA, CDS, UPSC, UPPSC and State PSC Examinations.
1.Which Vitamin is also known as Tocopherol?
Correct Answer: B [Vitamin E]
Notes:
Vitamin E is a series of organic compounds consisting of various methylated phenols. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was given the name “tocopherol” or birth carrying vitamin.
There are eight forms of Vitamin E. In general, food sources with the highest concentrations of vitamin E are vegetable oils, followed by nuts and seeds including whole grains.
Vitamin E is a series of organic compounds consisting of various methylated phenols. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was given the name “tocopherol” or birth carrying vitamin.
There are eight forms of Vitamin E. In general, food sources with the highest concentrations of vitamin E are vegetable oils, followed by nuts and seeds including whole grains.
2.Which among the following types of glasses contains Cerium and other rare earths and has a high absorption of ultraviolet rays?
Correct Answer: A [Crookes Glass]
Notes:
Crookes glass comprises Cerium oxide (CiO2) which sharply absorbs the ultraviolet rays from the sunlight. It is used in making lenses of eye glasses.
Crookes glass comprises Cerium oxide (CiO2) which sharply absorbs the ultraviolet rays from the sunlight. It is used in making lenses of eye glasses.
3.Which among the following is measured using a Vernier Caliper?
Correct Answer: A [Dimensions]
Notes:
The Vernier caliper has a main scale and a sliding vernier scale which can measure nearest to 0.02 mm. It can be used to measure internal and the external dimensions of an object by using the smaller jaws at the top and the main jaws respectively. By using stems depth can be measured.
The Vernier caliper has a main scale and a sliding vernier scale which can measure nearest to 0.02 mm. It can be used to measure internal and the external dimensions of an object by using the smaller jaws at the top and the main jaws respectively. By using stems depth can be measured.
4.Which of the following type of Coal has maximum carbon content?
Correct Answer: C [Antharacite]
Notes:
Anthracite, often referred to as hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.
Anthracite, often referred to as hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.
5.Butter is a ________?
Correct Answer: A [fat dispersed in milk]
Notes:
Butter is a fat dispersed in milk. It is usually made from cow’s milk, but can also be manufactured from the milk of other mammals, including sheep, goats, buffalo, and yaks.
Butter is a fat dispersed in milk. It is usually made from cow’s milk, but can also be manufactured from the milk of other mammals, including sheep, goats, buffalo, and yaks.
6.Who among the following scientists is known for developing techniques for DNA fingerprinting and DNA profiling which are now used all over the world in forensic science to assist police detective work?
Correct Answer: C [Alec Jeffreys]
Notes:
Alec Jeffreys scientists is known for developing techniques for DNA fingerprinting and DNA profiling which are now used all over the world in forensic science to assist police detective work.
Alec Jeffreys scientists is known for developing techniques for DNA fingerprinting and DNA profiling which are now used all over the world in forensic science to assist police detective work.
7.Which among the following diseases have been successfully eradicated from India through Immunization?
- Polio
- Smallpox
- Chicken Pox
- Leprosy
Select the correct option from the codes given below:
Correct Answer: A [ 1 & 2]
Notes:
India, which had once been the polio capital of the world, has now been free of the debilitating disease for three years. Polio is the second disease that has been eradicated from India. The country eradicated smallpox in 1980 following a successful sustained immunization campaign.
India, which had once been the polio capital of the world, has now been free of the debilitating disease for three years. Polio is the second disease that has been eradicated from India. The country eradicated smallpox in 1980 following a successful sustained immunization campaign.
8.The magnetic lines of force:
1. are closed continuous curves
2. travel from north to south outside the magnet and from south to north inside the magnet
3. bend along the length of magnet
4. mutually repel each other
5. never intersect each other
Which among the above is / are correct?
1. are closed continuous curves
2. travel from north to south outside the magnet and from south to north inside the magnet
3. bend along the length of magnet
4. mutually repel each other
5. never intersect each other
Which among the above is / are correct?
Correct Answer: D [ 1, 2, 3, 4 & 5]
Notes:
Magnetic lines of force are closed continuous curves in a magnetic field along which the north pole will move if free to do so and its direction is given by the direction in which free north pole will point. The five points given in this questions are its notable properties.
Magnetic lines of force are closed continuous curves in a magnetic field along which the north pole will move if free to do so and its direction is given by the direction in which free north pole will point. The five points given in this questions are its notable properties.
9.Which of the following observations about the elasticity of different materials is / are correct?
- Glass is more elastic than rubber
- Elasticity of steel is more than that of copper
Select the correct option from the codes given below:
Correct Answer: C [ Both 1 & 2]
Notes:
Elasticity of steel is more than that of copper and so for equal applied force, the elongation of steel spring is less than that of copper for same initial length. This implies that the steel spring can bear a larger tension before the elastic limit is crossed. Further, steel recovers its original state quicker than copper after the deforming force is removed. Due to this reason, steel is preferred in making springs in comparison to steel. The second statement is correct. Glass is more elastic than rubber because for a given applied force per unit area, the strain produced in glass is much smaller than produced in rubber.
Elasticity of steel is more than that of copper and so for equal applied force, the elongation of steel spring is less than that of copper for same initial length. This implies that the steel spring can bear a larger tension before the elastic limit is crossed. Further, steel recovers its original state quicker than copper after the deforming force is removed. Due to this reason, steel is preferred in making springs in comparison to steel. The second statement is correct. Glass is more elastic than rubber because for a given applied force per unit area, the strain produced in glass is much smaller than produced in rubber.
10. Consider the following differences between RNA and DNA:
- While DNA is usually found inside the nucleus, RNA is usually found in the cytoplasm
- DNA contains higher number of nucleotides in comparison to RNA
Which of the above statements is/are correct?
Correct Answer: C [ Both 1 & 2]
Notes:
Both are correct statements
Both are correct statements
11.All cells contain the same genetic information, yet cells other than stem cells can not differentiate into various tissues. What is the possible reason for this?
Correct Answer: B [ As cells develop some genes are turned off permanently.]
Notes:
As cells develop some genes are turned off permanently. All of the cells within a complex multicellular organism such as a human being contain the same DNA; however, the body of such an organism is clearly composed of many different types of cells. What, then, makes a liver cell different from a skin or muscle cell? The answer lies in the way each cell deploys its genome. In other words, the particular combination of genes that are turned on (expressed) or turned off (repressed) dictates cellular morphology (shape) and function. This process of gene expression is regulated by cues from both within and outside cells, and the interplay between these cues and the genome affects essentially all processes that occur during embryonic development and adult life. This means that cells become specialized because the genes that are not required are switched off. Only the genes needed to make a particular type of cell work are switched on. So muscle cells only have the genes needed to make muscle cell proteins switched on. All the other genes, such as those needed to make blood cell proteins and nerve cell proteins, are switched off. But the stem cells are unspecialized and can develop into various tissues.
As cells develop some genes are turned off permanently. All of the cells within a complex multicellular organism such as a human being contain the same DNA; however, the body of such an organism is clearly composed of many different types of cells. What, then, makes a liver cell different from a skin or muscle cell? The answer lies in the way each cell deploys its genome. In other words, the particular combination of genes that are turned on (expressed) or turned off (repressed) dictates cellular morphology (shape) and function. This process of gene expression is regulated by cues from both within and outside cells, and the interplay between these cues and the genome affects essentially all processes that occur during embryonic development and adult life. This means that cells become specialized because the genes that are not required are switched off. Only the genes needed to make a particular type of cell work are switched on. So muscle cells only have the genes needed to make muscle cell proteins switched on. All the other genes, such as those needed to make blood cell proteins and nerve cell proteins, are switched off. But the stem cells are unspecialized and can develop into various tissues.
12.Which of the following diseases is spread by mosquitoes but is not a viral disease?
Correct Answer: D [ Filariasis]
Notes:
Filariasis is a parasitic disease caused by an infection with roundworms of the Filarioidea type. These are spread by blood-feeding black flies and mosquitoes. Meningitis is an inflammation of the protective membranes covering the brain and spinal cord known as the meninges. The inflammation may be caused by infection with viruses, bacteria or other microorganisms. Yellow fever is an acute viral disease. It is caused by the yellow fever virus and is spread by the bite of an infected female mosquito.
Filariasis is a parasitic disease caused by an infection with roundworms of the Filarioidea type. These are spread by blood-feeding black flies and mosquitoes. Meningitis is an inflammation of the protective membranes covering the brain and spinal cord known as the meninges. The inflammation may be caused by infection with viruses, bacteria or other microorganisms. Yellow fever is an acute viral disease. It is caused by the yellow fever virus and is spread by the bite of an infected female mosquito.
13.Consider the following statements:
- Nephron is the primary filtering unit of the kidney
- Kidneys help in making red blood cells
Which of the above statements is/are correct?
Correct Answer: C [Both 1 & 2]
Notes:
Healthy kidneys produce a hormone called EPO. EPO prompts the bone marrow to make red blood cells. Nephron is the basic structural and functional unit of is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood.
Healthy kidneys produce a hormone called EPO. EPO prompts the bone marrow to make red blood cells. Nephron is the basic structural and functional unit of is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood.
14.What is the relationship between Kinetic and limiting friction?
Correct Answer: B [Kinetic friction is slightly less than limiting friction]
Notes:
The Kinetic friction is always slightly less than the limiting friction. This is because once the motion has started, the inertia of has been overcome and irregularities of one surface have little or no time to get locked into the irregularities of the other surface.
The Kinetic friction is always slightly less than the limiting friction. This is because once the motion has started, the inertia of has been overcome and irregularities of one surface have little or no time to get locked into the irregularities of the other surface.
15.What is the unit of Specific gravity?
Correct Answer: D [ No units ]
Notes:
Specific gravity is a unitless quantity. Specific gravity is the ratio of two same dimensions. The dimensions of density is M1 L– 3
Specific gravity is a unitless quantity. Specific gravity is the ratio of two same dimensions. The dimensions of density is M1 L– 3
16.What is the audible range of sound for human beings?
Correct Answer: C [20 Hz to 20000 Hz]
Notes:
The audible range of sound for human beings extends from about 20 Hz to 20000 Hz (one Hz = one cycle/s).
The audible range of sound for human beings extends from about 20 Hz to 20000 Hz (one Hz = one cycle/s).
17.Which of the following represents Charles’ law?
Correct Answer: B [Volume/Temperature = constant when Pressure is constant]
Notes:
When the pressure is held constant, the volume of a quantity of the gas is related to the temperature as V/T = constant. This relationship is known as Charles’ law.
When the pressure is held constant, the volume of a quantity of the gas is related to the temperature as V/T = constant. This relationship is known as Charles’ law.
18.Which of the following is true about a concave lens?
Correct Answer: B [power of a concave lens is negative]
Notes:
The power of a convex lens is positive and that of a concave lens is negative.
The power of a convex lens is positive and that of a concave lens is negative.
19.Which of these ores is not an oxide?
Correct Answer: A [Sphalerite]
Notes:
Sphalerite (ZnS) is a sulphide. All others are oxides. Haematite and Magnetite are the oxides of iron and Cuprite is an oxide of Copper.
Sphalerite (ZnS) is a sulphide. All others are oxides. Haematite and Magnetite are the oxides of iron and Cuprite is an oxide of Copper.
20.Which of the following is the characteristic of water present in coconut?
Correct Answer: D [degenerated liquid endosperm]
Notes:
The coconut water from tender coconut that we are familiar with, is nothing but free nuclear endosperm (made up of thousands of nuclei) and the surrounding white kernel is the cellular endosperm. In the most common types of endosperm development, the Primary Endosperm Nucleus (PEN) undergoes successive
The coconut water from tender coconut that we are familiar with, is nothing but free nuclear endosperm (made up of thousands of nuclei) and the surrounding white kernel is the cellular endosperm. In the most common types of endosperm development, the Primary Endosperm Nucleus (PEN) undergoes successive
21.Bulbil takes part in which of the following processes in plants?
Correct Answer: D [Vegetative reproduction]
Notes:
Bulbil, also called bulblet, in botany, is a tiny secondary bulb that forms in the angle between a leaf and stem or in place of flowers on certain plants for vegetative reproduction. Bulbils, called offsets when full-sized, fall or are removed and planted to produce new plants.
Bulbil, also called bulblet, in botany, is a tiny secondary bulb that forms in the angle between a leaf and stem or in place of flowers on certain plants for vegetative reproduction. Bulbils, called offsets when full-sized, fall or are removed and planted to produce new plants.
22.
What is the status of total energy at any time during the interconversion of energy from one form to other forms?
Correct Answer: A [The total energy remains constant.]
Notes:
During interconversion of energy from one form to other forms, total energy at any time remains constant. First Law of Thermodynamics: Energy can be changed from one form to another, but it cannot be created or destroyed. The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. The First Law of Thermodynamics (Conservation) states that energy is always conserved, it cannot be created or destroyed. In essence, energy can be converted from one form into another.
23.Which of the following branch of biology deals with the study of viruses?
Correct Answer: C [Virology]
Notes:
Virology, the branch of microbiology that deals with the study of viruses.
Virology, the branch of microbiology that deals with the study of viruses.
24.In the branch of biology which of the following deals with the Study of kidney?
Correct Answer: A [Nephrology]
Notes:
Nephrology is a specialty of adult internal medicine and pediatrics that deals with the study of the kidneys, particularly normal kidney function (kidney physiology) and kidney disease.
Nephrology is a specialty of adult internal medicine and pediatrics that deals with the study of the kidneys, particularly normal kidney function (kidney physiology) and kidney disease.
25.Which of the following inventions is Samuel Hahnemann related?
Correct Answer: A [Homeopathy]
Notes:
Homeopathy was developed in the early 19th century by the German physician and pharmacist Samuel Hahnemann (1755–1843).
Homeopathy was developed in the early 19th century by the German physician and pharmacist Samuel Hahnemann (1755–1843).
26.On which of the following criteria is the five-state system done?
Correct Answer: D [Mode of Nutrition]
Notes:
The main criteria of the five kingdom classification were cell structure, body organisation, mode of nutrition and reproduction, and phylogenetic relationships.
The main criteria of the five kingdom classification were cell structure, body organisation, mode of nutrition and reproduction, and phylogenetic relationships.
27.Which of the following contains an anticodon?
Correct Answer: A [tRNA]
Notes:
An anticodon is found at one end of the transfer RNA (tRNA) molecule. During protein synthesis, each time an amino acid is added to the growing protein. A tRNA forms base pairs with its complementary sequence on the mRNA molecule and ensures that the appropriate amino acid is inserted into the protein.
An anticodon is found at one end of the transfer RNA (tRNA) molecule. During protein synthesis, each time an amino acid is added to the growing protein. A tRNA forms base pairs with its complementary sequence on the mRNA molecule and ensures that the appropriate amino acid is inserted into the protein.
28.Which one of the following plants has seeds but no flowers and fruits?
Correct Answer: B [Gymnosperms]
Notes:
Gymnosperms are a group of seed-producing plants. These include conifers, cycads, ginkgo and gnatophytes, which make up the clade gymnosperms. These living members are also known as acrogynosperms.
Gymnosperms are a group of seed-producing plants. These include conifers, cycads, ginkgo and gnatophytes, which make up the clade gymnosperms. These living members are also known as acrogynosperms.
29.Bacteria used in making of chocolate__?
Correct Answer: B [Lactobacillus cacaonum]
Notes:
Lactobacillus cacaonum is a bacteria used in the food packaging industry for making chocolates. Lactobacillus bucheri is helpful in making wine. Lactobacillus casei is used in making cheese. Monosodium glutamate is used in Chinese food to enhance taste.
Lactobacillus cacaonum is a bacteria used in the food packaging industry for making chocolates. Lactobacillus bucheri is helpful in making wine. Lactobacillus casei is used in making cheese. Monosodium glutamate is used in Chinese food to enhance taste.
30.External ears are characteristics of:
Correct Answer: B [Mammals]
Notes:
External ears are characteristics of Mammals. Mammals have hair or fur, are warm-blooded and most are born alive
External ears are characteristics of Mammals. Mammals have hair or fur, are warm-blooded and most are born alive
31.Equisetum is an example of__?
Correct Answer: B [pteridophytes]
Notes:
Equisetum is an example of pteridophytes. Hornworts, liverworts, and mosses are all examples of bryophytes. Cycas, pinus, Thuja, Cedrus, Abies, Larix are some of the examples of gymnosperms.
Equisetum is an example of pteridophytes. Hornworts, liverworts, and mosses are all examples of bryophytes. Cycas, pinus, Thuja, Cedrus, Abies, Larix are some of the examples of gymnosperms.
32.An anaerobic process in which energy can be released from glucose even when oxygen is not available is called__.
Correct Answer: B [Fermentation]
Notes:
An anaerobic process in which energy can be released from glucose even when oxygen is not available is called Fermentation.
An anaerobic process in which energy can be released from glucose even when oxygen is not available is called Fermentation.
33.Which of the following are pneumatophores?
Correct Answer: A [that grow in swampy areas have roots growing vertically upwards]
Notes:
Roots of some plants growing in marshy areas grow vertically upwards to obtain oxygen for respiration. These roots are known as pneumatophores.
Roots of some plants growing in marshy areas grow vertically upwards to obtain oxygen for respiration. These roots are known as pneumatophores.
34.Filariasis is caused by __.
Correct Answer: A [roundworms]
Notes:
Filariasis is caused by roundworms. Lymphatic filariasis is caused by Wuchereria bancrofti, Brugia timori and Brugia malayi. This causes thickening of the skin and tissues present under the skin.
Filariasis is caused by roundworms. Lymphatic filariasis is caused by Wuchereria bancrofti, Brugia timori and Brugia malayi. This causes thickening of the skin and tissues present under the skin.
35.Chameleons are examples of which class of reptiles?
Correct Answer: A [Diapsida]
Notes:
Chameleon is an example of the Diapsida class of reptiles. They are diverse of all reptiles and have two temporal recesses in their skulls.
Chameleon is an example of the Diapsida class of reptiles. They are diverse of all reptiles and have two temporal recesses in their skulls.
36.The brainstem consists of which of the following
Correct Answer: A [Tectum and Tegmentum]
Notes:
The brainstem consists of Tectum and Tegmentum. The midbrain tegmentum is the part of the midbrain that extends from the substantia nigra to the cerebral aqueduct. The tectum is the dorsal side of the midbrain.
The brainstem consists of Tectum and Tegmentum. The midbrain tegmentum is the part of the midbrain that extends from the substantia nigra to the cerebral aqueduct. The tectum is the dorsal side of the midbrain.
37.What is the difference between compact bone and spongy bone?
Correct Answer: D [They have different arrangement of bone cells]
Notes:
The cells in the compact bone are packed closely together. This makes the bone very strong. For this reason, compact bone is located outside the bones. The spongy bone cells are dilated, which allows blood-filled canals to run through the spongy bone. The spongy bone is found at the end of long bones.
The cells in the compact bone are packed closely together. This makes the bone very strong. For this reason, compact bone is located outside the bones. The spongy bone cells are dilated, which allows blood-filled canals to run through the spongy bone. The spongy bone is found at the end of long bones.
38.What is the role of the atrioventricular valves?
Correct Answer: C [prevent blood from flowing back into the atria]
Notes:
When the ventricles contract, the atrioventricular valves close to prevent blood from flowing back into the atria.
When the ventricles contract, the atrioventricular valves close to prevent blood from flowing back into the atria.
39.What is the best long-term solution for kidney failure?
Correct Answer: A [Kidney transplant]
Notes:
A kidney transplant is the best long-term solution for kidney failure. Complete failure of the kidneys allows urea and other waste products to build up in the blood.
A kidney transplant is the best long-term solution for kidney failure. Complete failure of the kidneys allows urea and other waste products to build up in the blood.
40.Complete digestion of food takes place in:
Correct Answer: B [Small Intestine]
Notes:
Complete digestion of food takes place in Small Intestine. The small intestine carries out most of the digestion process, absorbing almost all of the nutrients from foods into your bloodstream.
Complete digestion of food takes place in Small Intestine. The small intestine carries out most of the digestion process, absorbing almost all of the nutrients from foods into your bloodstream.
41.Blue-Green algae are __
Correct Answer: A [Symbiotic Nitrogen-Fixing Cyanobacteria]
Notes:
Blue-Green algae are Symbiotic Nitrogen-Fixing Cyanobacteria. Liverworts, cycad roots, fern, and lichens are also some of the Nitrogen-fixing cyanobacteria.
Blue-Green algae are Symbiotic Nitrogen-Fixing Cyanobacteria. Liverworts, cycad roots, fern, and lichens are also some of the Nitrogen-fixing cyanobacteria.
42.Which of the followings is the character of a bond between two atoms is greater if the difference in their electro negativities is lesser?
Correct Answer: D [Covalent]
Notes:
The type of bond formed between two atoms depends upon the difference in their electronegativities. If the difference in electronegativities is zero or very small, the bond formed would be covalent and if the difference exceeds 2.5, the bond formed would be electrovalent. In simple words, Lesser the difference in electronegativity of two atoms, the bond formed will be covalent; higher the difference, the bond formed will be electrovalent.
The type of bond formed between two atoms depends upon the difference in their electronegativities. If the difference in electronegativities is zero or very small, the bond formed would be covalent and if the difference exceeds 2.5, the bond formed would be electrovalent. In simple words, Lesser the difference in electronegativity of two atoms, the bond formed will be covalent; higher the difference, the bond formed will be electrovalent.
43.Nitrogen is an essential constituent of all :
Correct Answer: B [Proteins]
Notes:
Nitrogen is a major constituent of all proteins, and thus of all living organisms. The deficiency of nitrogen causes yellowing of older leaves, stunted plants, dormancy of lateral buds, purple colouration in shoot axis surface, wrinkling of cereal grains and inhibition of cell division. In humans, its deficiency cause PCM that leads to retarded body growth in form of Marasmus and kawashikor.
Nitrogen is a major constituent of all proteins, and thus of all living organisms. The deficiency of nitrogen causes yellowing of older leaves, stunted plants, dormancy of lateral buds, purple colouration in shoot axis surface, wrinkling of cereal grains and inhibition of cell division. In humans, its deficiency cause PCM that leads to retarded body growth in form of Marasmus and kawashikor.
44.The gas used to extinguish fire is:
Correct Answer: C [Carbon dioxide]
Notes:
Fires require these 3 things: a fuel (an inflammable hydro carbon) a source of oxygen, and heat. Carbon dioxide is most commonly used to extinguish fire as it is non-supporter of combustion and also being heavier air displaces oxygen, thus choking the very source of a fire.
Fires require these 3 things: a fuel (an inflammable hydro carbon) a source of oxygen, and heat. Carbon dioxide is most commonly used to extinguish fire as it is non-supporter of combustion and also being heavier air displaces oxygen, thus choking the very source of a fire.
45.The most abundant element is:
Correct Answer: C [Oxygen]
Notes:
On earth, oxygen is the most common element, making up about 47% of the earth’s mass. Silicon is second, making up 28%, followed by aluminum (8%), iron (5%), magnesium (2%), calcium (4%), sodium (3%), and potassium (3%). All of the remaining elements together make up less than 1% of the earth’s mass.
On earth, oxygen is the most common element, making up about 47% of the earth’s mass. Silicon is second, making up 28%, followed by aluminum (8%), iron (5%), magnesium (2%), calcium (4%), sodium (3%), and potassium (3%). All of the remaining elements together make up less than 1% of the earth’s mass.
46.Which one of the following non-metals shows allotropy in the liquid state?
Correct Answer: B [Sulphur]
Notes:
Sulphur is a non-metal that shows allotropy in the liquid state. If sulphur is heated slowly the changes between the different forms can be observed. These changes are in the form of colour and viscosity (thickness) of the liquid. If the dark brown liquid sulphur is poured into a beaker of cold water, plastic sulphur is formed. This is an elastic, rubber-like form of sulphur. The tow commonly know allotropic forms of sulphur are monoclinic and rhombhic sulphur.
Sulphur is a non-metal that shows allotropy in the liquid state. If sulphur is heated slowly the changes between the different forms can be observed. These changes are in the form of colour and viscosity (thickness) of the liquid. If the dark brown liquid sulphur is poured into a beaker of cold water, plastic sulphur is formed. This is an elastic, rubber-like form of sulphur. The tow commonly know allotropic forms of sulphur are monoclinic and rhombhic sulphur.
47.Atomic number of which of the following elements is greater than that of Fluorine?
Correct Answer: A [Sodium]
Notes:
Sodium has higher atomic number (11) than Fluorine (9). The atomic number of Beryllium and Nitrogen are 4 and 7 respectively. Atomic number is the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.
Sodium has higher atomic number (11) than Fluorine (9). The atomic number of Beryllium and Nitrogen are 4 and 7 respectively. Atomic number is the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.
48.Which of the following is the structure of graphite?
Correct Answer: B [Hexagonal]
Notes:
Graphite is a naturally-occurring form of crystal-line carbon. It is a native element mineral found in metamorphic and igneous rocks. The carbon atoms in graphite are linked in a hexagonal network which forms sheets that are one atom thick. These sheets are poorly connected and easily cleave or slide over one another if subjected to a small amount of force. This gives graphite its very low hardness, its perfect cleavage, and its slippery feel.
Graphite is a naturally-occurring form of crystal-line carbon. It is a native element mineral found in metamorphic and igneous rocks. The carbon atoms in graphite are linked in a hexagonal network which forms sheets that are one atom thick. These sheets are poorly connected and easily cleave or slide over one another if subjected to a small amount of force. This gives graphite its very low hardness, its perfect cleavage, and its slippery feel.
49.What is the chemical symbol of ‘Iron’?
Correct Answer: B [Fe]
Notes:
Iron is a chemical element with symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth’s outer and inner core.
Iron is a chemical element with symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth’s outer and inner core.
50.Which of the following substances is used as a substitute for chlorine in bleaching?
Correct Answer: C [Hydrogen peroxide]
Notes:
Hydrogen peroxide (H2O2) is a greener alternative to chlorine (Cl2).
Hydrogen peroxide (H2O2) is a greener alternative to chlorine (Cl2).
- Hydrogen Peroxide is simply water with an extra oxygen molecule (H2O2) and breaks down into oxygen and water.
- Chlorine dioxide (ClO2) and sodium hypochlorite (NaOCl) that are traditionally used for bleaching color from substances.