Description : Crystalline silicon is obtained by reducing
Last Answer : silica with coke.
Description : Compare the properties of amorphous and crystalline silicon
Last Answer : morphous silicon It is a brown powder It does not conduct electricity at low temperatures. It is more reactive than crystalline silicon When heated in air, it oxidizes at the surface level ... electricity It is less reactive than amorphous silicon It does not burn in air even when heated
Description : Charcoal is (a) Amorphous (b) Crystalline (c) Hygroscopic (d) None of these
Last Answer : Ans:(a)
Description : Diamond is the form of carbon that is (a) Crystalline (b) Amorphous (c) Chemical (d) Alkaline
Description : The crystalline forms of carbon are
Last Answer : diamond and graphite.
Description : Why is diamond hard whereas graphite soft even through both are crystalline forms of carbon?
Last Answer : The reason for difference is because of arrangement of carbon atoms.
Description : All of the following substances are crystalline except-------? A. Ice B. Diamond C. Sucrose D. Plastic (Answer)
Last Answer : D. Plastic (Answer)
Description : In what three components of Earth's makeup must we find the total mass of crystalline rock components that were eroded from the primary crystalline rocks of earth's surface?
Last Answer : answer:What are the components of Earth’s makeup? How many are there? Wouldn’t it be the components nearest the surface (e.g., crust, lithosphere, asthenosphere)? Keep in mind, I have no idea what I’m talking about.
Description : The Peninsular plateau is a tableland composed of the old crystalline, igneous and metamorphic rocks. What do CRYSTALLINE ROCKES mean here? -Geography
Last Answer : Crystalline rock, any rock composed entirely of crystallized minerals without glassy matter. Metamorphic rocks are almost always crystalline; the term crystalline schists has been applied to indicate all rocks ... origin, and thus the term crystalline rocks may be taken to mean an igneous origin.
Description : Which is a part of the eye that helps in changing the focal length of crystalline lensis? -Do You Know?
Last Answer : answer:
Description : What is the composition of crystalline water in blue vitriol ?
Last Answer : : Blue vitriol's crystal water content is 36.06%.
Description : A yellow coloured crystalline substance gave a colourless gas `X` on reaction with fluorine, which is thermally stable and has octahedral geometry. `X
Last Answer : A yellow coloured crystalline substance gave a colourless gas `X` on reaction with fluorine, which is ... and has octahedral geometry. `X` can be
Last Answer : A yellow coloured crystalline substance gave a colourless gas `X` on reaction with fluorine, which is thermally stable ... `SF_(2)` D. `S_(2)F_(6)`
Description : White crystalline solid (A) reacts with `H_2` to form a highly associated liquid (B) and a monoatomic , colourless gas (C ). The liquid (B) is used fo
Last Answer : White crystalline solid (A) reacts with `H_2` to form a highly associated liquid (B) and a ... has only unpaired electron in `pi` molecular orbital.
Last Answer : White crystalline solid (A) reacts with `H_2` to form a highly associated liquid (B) and a ... metallic bonds D. ionic, covalent and Hydrogen bonds
Last Answer : White crystalline solid (A) reacts with `H_2` to form a highly associated liquid (B) and a monoatomic , colourless gas ... 3)d` D. V - shape, `sp^(3)`
Description : A crystalline solid X reacts with dilute HCl to liberate a gas Y. The gas Y decolourises acidified `KMnO_(4)`. When a gas Z is slowly passed into aque
Last Answer : A crystalline solid X reacts with dilute HCl to liberate a gas Y. The gas Y decolourises acidified `KMnO_(4)`. When ... 2)S` D. `Na_(2)SO_(4),SO_(2)`
Description : Crystalline form of Sulphur is
Last Answer : Crystalline form of Sulphur is A. Plastic sulphur B. Colloidal sulphur C. Monoclinic sulphur D. All of these
Description : What happens when crystalline Na2CO3 is heated ?
Last Answer : What happens when crystalline Na2CO3 is heated ? a. releases CO2 b. loses H2O c. decomposes into NaHCO3 d. colour changes.
Description : What naturally occurring inorganic crystalline solid is a?
Last Answer : a mineral
Description : Is a marshmallow a crystalline solid?
Last Answer : Marshmallows are amorphous solids.
Description : The Himalayan region is poor in mineral resources because (a) it is made up of crystalline rocks (b) displacement of rock strata has disturbed the arrangement of rocks and made it ... minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties
Last Answer : Ans: (b)
Description : The Himalayan region is poor in mineral resources because: [IAS 2004] (a) it is made of crystalline rocks (b) the displacement of rock strata has disturbed the arrangement of rock and ... minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties
Description : Which of the following is/are not the characteristics of red soils? 1. They are derived from weathering of old crystalline and metamorphic rocks 2. They contain iron oxides 3. They have high water retention capacity 4. They ... nitrogen content (a) II and III (b) Only III (c) Only IV (d) III and IV
Last Answer : Ans: (d)
Description : The Red soils develop a reddish colour due to: (a) deforestation and over-grazing (b) the presence of potash and magnesia (c) tropical monsoonal climate (d) a wide diffusion of iron in ancient crystalline and metamorphic Jacks
Description : Why is it that the Himalayan region is poor in mineral resources? (a) Displacement of rock strata has disturbed the arrangement of rocks and made it complex (b) It is made up of ... makes exploitation of minerals difficult (d) The climatic conditions are not suitable, for exploitation of minerals
Last Answer : Ans: (a)
Description : In the genetic disorder of cystinuria, the patient excretes large quantities of cystine in their urine and its low solubility causes crystalline cystine to precipitate as stones in kidneys. The remedy ... C) NaHCO3 prevents stone formation by hydrolysis of cystine to cysteine (D) None of these
Last Answer : Answer : C
Description : Diamond does not conduct electricity, because - (1) It's structure is very compact (2) It is of crystalline nature (3) There are only carbon atoms present in it (4) No free electrons are present in it
Last Answer : (4) No free electrons are present in it Explanation: Diamond has a giant molecular structure. Each carbon atom is covalently bonded to four other car-bon atoms. There are no ... conduct electricity. Except for most blue diamonds, which are semiconductors, diamonds are good electrical insulators.
Description : (4) Decomposition of manganese dioxide Explanation: One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese nitrate ... 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.
Last Answer : The mass number of a nucleus is - (1) always less than its atomic number (2) the sum of the number of protons and neutrons present in the nucleus (3) always more than the atomic weight (4) a fraction
Description : Diamond is the form of carbon that is - (1) Crystalline (2) Amorphous (3) Chemical (4) Alkaline
Last Answer : (1) Crystalline Explanation: Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.
Description : Glass is - (1) Super cooled liquid (2) Crystalline solid (3) Liquid crystal (4) None of these
Last Answer : (1) Super cooled liquid Explanation: Glass is sometimes called a Super cooled liquid because it does not form a crystalline structure, but instead forms an amorphous solid that allows molecules in the material to continue to move.
Description : Diamond is harder than graphite because of – (1) difference in layers of atoms (2) tetrahedral structure of diamond (3) difference of crystalline structures (4) None of these
Last Answer : (1) difference in layers of atoms Explanation: Diamond is harder than graphite because diamond has a more complex structure. Diamond's structure is like many pentagons connected together, each pentagon ... together in some way. Graphite's structure is very loose, with its bonds forming layers.
Description : Quartz is a crystalline form of - (1) Alumina (2) Glass (3) Silica (4) Limestone
Last Answer : (3) Silica Explanation: Quartz is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. Tridymite ... is a denser polymorph of quartz found in some meteorite impact sites and in metamorphic rocks.
Description : Fullerene is a newly discovered crystalline carbon allotrope, contains–
Last Answer : 60 C atoms
Description : A quarter wavelength devices made of crystalline calcite that changes polarization in the optic fiber communication. A. Isolator B. Retarder C. Polarizer D. Filters
Last Answer : B. Retarder
Description : Most of the fibre forming polymers are crystalline in nature, one of the exceptions being __________ which is amorphous in nature. (A) Nylon (B) Polyacrylonitrile (C) Polypropylene (D) Polyester
Last Answer : (B) Polyacrylonitrile
Description : Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to ... D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Description : . The physical state in which polymers exist is (A) Melts & rubber like state (B) Amorphous glassy state (C) Partially crystalline state (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The behaviour of visco-elastic material is time dependent. This behaviour is common in __________ materials. (A) Non-crystalline solid (B) Crystalline (C) Rubbery (D) Non-crystalline organic polymeric
Last Answer : (D) Non-crystalline organic polymeric
Description : Common house hold glass (i.e., soda-lime glass) is a/an __________ material. (A) Fully crystalline (B) Partly crystalline (C) Amorphous
Last Answer : (B) Partly crystalline
Description : Visco-elastic behaviour of materials which is time dependent is common in (A) Plastics (B) Crystalline solid (C) Non-crystalline solids (D) Non-crystalline organic polymer
Last Answer : (D) Non-crystalline organic polymer
Description : Combination of metals and ceramics are called (A) Metalloy (B) Cermets (C) Pellets (D) Non-crystalline ceramics
Last Answer : (B) Cermets
Description : For continuous drying of granular or crystalline material, the dryer used is the __________ dryer. (A) Tunnel (B) Tray (C) Rotary (D) None of these
Last Answer : (C) Rotary
Description : Write the three crystalline forms in which Boron exist.
Last Answer : Ans.a) Prismatic Borax (Na2B4O7.10H2O) b) Octahedral Borax (Na2B4O7.5H2O) c) Anhydrous Sodium tetra borate (Na2B4O7
Description : Predict the entropy change in- (i) A liquid crystallizes into solid (ii) Temperature of a crystalline solid raised from 0K to 115K.
Last Answer : Ans. (i) Entropy decreases because molecules attain an ordered state. (ii) Entropy increases because from 0K to 115K average kinetic of moleculesincreases.
Description : Fibres are of crystalline structure. Why ?
Last Answer : Ans. Fibres have strong intermolecular forces of attraction which leads to close packing of their chains and impart crystalline structure.
Description : Why are powdered substances more effective absorbents than their crystalline forms?
Last Answer : Ans. Due to increase of surface area of powered substances.