Ans: Three important uses of hydrogen are: Ans:(i) to manufacture ammonia gas, which is used to manufacture fertilizers such as urea and ammonium sulphate. (c) Cooking food in an open pan on low flame, ► (c) Cooking food in an open pan on low flame. Ans: Silverware becomes black faster today than it did fifty years ago because of air pollution. Oxygen is evolved at the anode which reacts with aluminium to form a uniform protective layer of aluminium oxide. These metals are typically sourced from large mining operations in Africa and Asia, then exported to the rest of the world for commercial and industrial use. Why sodium and potassium stored in kerosene? Required fields are marked *. Try to hit hard. (b) Covering with another metal: Depositing a layer of another metal which is more resistant to corrosion is another commonly used method. As they are unreactive, they are used to make ornaments. ► (a) To convert mineral ores into useful materials. Copper is another metal used in everything from coins to pipes. 16. Noble metals – Gold, silver and platinum are noble metals. They occur free in nature . 1. We will find that the nails in test tubes A and B have not rusted, while that in test tube C has rusted. NCERT Solutions; _Class 6 ; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12; Revision Notes; _Class 6; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12; Important Questions; _Class 6; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12; Download App; Watch Videos; Download App. 9. Explain. (a) Ductility(b) Sonorous(c) Dullness(d) Electrical conductionAnswer:(c), Question 2.The most abundant element in the universe is(a) hydrogen(b) oxygen(c) helium(d) carbonAnswer:(a), Question 3.The ability of metals to be drawn into wires is known as(a) ductility(b) conductivity(c) malleability(d) sonorousityAnswer:(a), Question 4.The most abundant element in the earth crust is(a) iron(b) oxygen(c) silicon(d) aluminiumAnswer:(b), Question 5.Galvanisation is a method qf protecting iron from rusting by coating with a thin layer of(a) silver(b) galium(c) zinc(d) aluminiumAnswer:(c), Question 6.The most abundant ihetal in earth crust is(a) Cu(b) Al(c) Fe(d) ZnAnswer:(b), Question 7.An alloy is(a) a compound(b) a heterogeneous mixture(c) a homogeneous mixture(d) an elementAnswer:(c), Question 8.In extraction of copper, the flux used is(a) FeO(b) Si02(c) CaO(d) FeSi03Answer:(b), Question 9.Alloys are homogeneous mixtures of a metal with a metal or non-metal. 2. copper sulphate and ironc. 14. copper,aluminium. Silver tarnishes black with a surface layer of acanthite (silver sulphide), especially when placed in proximity to sulphurous compounds. ( ), Copper displaces zinc from zinc sulphate solution. Give two examples of non- metallic mineral fuels from the options given below: 3. Also write the equation of the reaction. Oxygen is evolved at the anode which reacts with aluminium to form a uniform protective layer of aluminium oxide. In such lattices there exist no atomic planes distinguished by higher or lower density; minerals of the gold group therefore demonstrate hackly fracture and possess no cleavage. Electrolytic copper was once traded principally in "wire bar," which was ready for the wire-drawing process. Differentiate between a rock and an ore. Answer: A rock is an aggregate of one or more minerals. 2. Silver is rarely found as a native element mineral. Example: stainless steel is an alloy of iron, chromium and nickel, does not rust easily. Which one among the following is not a physical property with respect to the minerals? Give an example. Nothing will happen as copper does not react with hydrochloric acid. Pure gold cannot be used for making jewellery because it is very soft. Gold foils are used in the preparation of Ayurvedic medicines. 5. All metals exist in solid form at room temperature. An alloy is usually made by mixing together metals in their molten form. Platinum, gold and silver are used for making jewellery as they do not tarnish. Silver as a Native Element Mineral. 2Na + 2H2O ———–> 2NaOH + H2, (ii) Magnesium reacts with hot water or steam. From the following options given, pick out the correct reason as to why impurities should be removed from mineral ores? What happen as a result of the reaction, Answer: Carbon is a non metal. 1. Thus, it will not replace iron from iron sulphate. (a) Amalgam(b) Brass(c) Bronze(d) SteelAnswer:(d), Question 10.Which of the following is purest form of carbon? Which gas will be liberated when metals react with cold water ? Why are musical instrument and bell made up of metal? Give reasons. Name one metal which will fit each of the following description. 6. They do not losetheir shine easily. iron sulphate and coppere. What do you think the tablets contained?Ans: The tablets contain iron in its compound form. Making x-ray shield and bullets: – lead7. Which among the following aljoys contain non-metal as one of its constituents? Which among the following is a leading producer of tin in the world? NCERT Solutions; _Class 6; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12 ; Revision Notes; _Class 6; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12; Important Questions; _Class 6; _Class 7; _Class 8; _Class 9; _Class 10; _Class 11; _Class 12; Download App; Watch Videos; Download App. How is anodizing of aluminium carried out? (d) Zinc sulphate and iron: A displacement reaction will not occur here because iron is placed below zinc. Write word equations of the reactions involved. Why is phosphorous stored under water? What do you observe? To understand rocks you need to become familiar with minerals and how they are identified. 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) + heat energy. 6. Aluminium is used to make electrical wire. (c) A metal which is used for galvanising iron. (b) One metal which is used to prepare hydrogen gas in the laboratory. It never tarnishes, and is unaffected by most chemicals. True iv. as in my school class 8th book the minerals found in south america are as follows : 1-copper 2-gold 3-iron ore 4-diamond 5-tin 6-nitrates 7-manganese 8-silver and 9-bauxite Minerals can be identified on the basis of their physical properties. Created on June 15, 2020 By Admin. THE DEFINITION OF ORGANIC: Organic chemistry is the study of those substances containing carbon in combination with hydrogen (H), and a few other non metals, namely oxygen (O), nitrogen (N), sulfur (S) and the halogens (F 2 , Cl 2 , Br 2 , and I 2 ). Can alloying be used to lower the melting point? and maintain their lustre for a long time. Ore:-is a mineral from which metals can be extracted profitably. (a) Applying paint(b) Applying grease(c) Applying a coating of zinc(d) all of theseAnswer:(c), Question 13.Generally, non-metals are not conductors of electricity, which of the following is a good conductor of electricity? It is probably the oldest precious metal known to humans. (iii) in oxy-hydrogen flame for cutting and welding metals. Filling electric bulb – Argon 2. Ans: The reaction of metals with oxygen, water and acids shows that metals have different reactivates.Potassium and sodium are the most reactive whereas silver and gold are the least reactive.An arrangement of metals in decreasing order of reactivity is called the reactivity series of metals. Potassium after combustion will form (acidic oxide/basic oxide). 5. 4. The following reaction occurs:C (red hot) + O2 ————–> (H2 + CO) water gas, Your email address will not be published. 4. True v. Gold, silver and copper are ferrous mineral. Quiz on Mineral and Power Resources – Class 8. by Admin. 7. Minerals:-are elements or compounds which occur naturally inside . CBSE Previous Year Question Paper for Class 10, CBSE Previous Year Question Paper for Class 12. We can’t use pure gold to make jewellery. On exposure to air, they get oxidized. Identify the groups in which minerals are classified and their characteristics. Graphite is a good conductor of electricity, therefore, it is used as an electrode in dry cell. 15. (Iodine/bromine) has antiseptic properties. 2. Save my name, email, and website in this browser for the next time I comment. Applying grease or oil on the surface has a similar effect. Silver does not corrode and it is malleable and ductile, therefore, it can be used in jewellery. A doctor diagnosed a patient with iron deficiency, and gave him tablets containing iron. Types of minerals resources | mineral resources use and exploitation along with types of minerals and their uses @Byju's. Close the test tube with a cork. The activity shows that for rusting to take place, both air (oxygen) and water are essential. Which of the above metals is stored in kerosene ? Aluminium is above iron in the reactivity series. 3. 13. An iron knife kept dipped in blue copper sulphate solution changes to light green because iron replaces copper from copper sulphate and forms iron sulphate. making accurate laboratory balances f. making bodies of ships, Ans. zinc sulphate and copperd. Constructing bridge: – Iron3. To know what type of rock is gold associated with you must see that the minerals most common in placer deposits are platinum, iridosmine, magnetite, iron pyrites, ilmenite, zircon, garnets, rutile and barytes; wolfram, scheelite, brookite and diamonds are less common. zinc sulphate and ironf. Sulphur is the main constituent of skin ointments. The group is composed of only six minerals: gold, silver, copper, mercury, aluminum and lead. They are also sometimes made by mixing metal powders together. Half-fill test tube C with tap water and drop the nail in it. Which one of the followings is not the way of saving energy at home? Which of the metals become black in the presence of hydrogen sulphide ? Strong generalities exist in this class. Studyrankers is a free educational platform for cbse k-12 students. Name the country with the largest reserve of iron ore. 2. Give reasons. Physical Properties of Metals and Non-metals. 4. 5. This is the advantage of galvanized iron over tin-plated iron. 2. Most reactive metal is K and least reactive metal is Au. Identify the most reactive and least reactive metal amongst the followings : An iron knife kept dipped in blue copper sulphate solution changes to light green. 2Cu + O2 → 2CuO; 4Al + 3O2 → 2Al2O3. Mineral Class: Gold: Gold AUCTIONS: ALL ABOUT: Gold is the most malleable and ductile metal, which makes it very easy to work with. It can only be stored in a liquid hydrocarbon like mineral oil or kerosene oil. Silver is used in jewelry, tableware, coins, scientific equipment and in photographic processes. 1. Close the test tube with a cork.In test tube B, take some pure (distilled) water. Water purification: Chlorine 8. Many types of minerals and rocks exist on Earth. Silver has the ability to reflect light, therefore, it is used for making mirrors. This is why graphite is not used for making electric cable. Copper is used in electrical wiring because it is a good conductor of electricity. A native element and precious metal, gold has long been prized for its beauty, resistance to chemical attack and workability. Where are the ores of metallic minerals generally located? MCQ Questions for Class 8 Geography: Ch 3 Mineral and Power Resource. Ans: Aqua regia, (Latin for ‘royal water’) is a mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3:1. Generally, non-metals react with acids. Used for Names Composition(a) Making statues bronze copper, tin(b) Joining wires in electronic equipment solder lead, tin(c) Making surgical instrument stainless steel Iron, chromium, nickel(d) Making bodies of aircraft duralumin aluminium, copper, magnesium, manganese(e) Making accurate laboratory balances magnalium aluminium, magnesium(f) Making bodies of ships steel iron, carbon. What is an alloy? Could you store 500 ml Zinc sulphate solution in an aluminum vessel overnight? a. copper sulphate and zincb. A metal ribbon bums in air with bright white light and forms a white powder. Silver is one of the most famous precious metals, and has been used for ornamental purposes since the earliest of times. Metals like K and Na react vigorously with cold water to form hydrogen gas. 6. It can dissolve gold, even though neither of these acids can do so alone. ( ). Metallic sulphides of sulphur are used in the preparation of Ayurvedic medicines. Solder an alloy of lead and tin has a melting point much lower than that of lead and tin. Platinum, gold and silver are used for making jewellery as they do not tarnish. Gold is alloyed with copper to make it hard. Why are bells made of metals and not from wood? Aluminium is a highly malleable metal and can be made into foils. Magnesium reacts with cold water. What is the percentage’of gold in the ornaments ? (a) Alnico(b) Solder(c) Stainless steel(d) Zinc AmalgamAnswer:(d), Question 12.Which of the following methods is suitable for preventing an iron frying pan from rusting? Then drop in the nail. The Sulfide Class minerals comprise an economically important class of minerals. , pick out the one that is brittle and can be made into foils, )... Is evolved at the anode which reacts with it to form a uniform protective layer of cotton salt. 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