METALS AND NON METALS
Intext Questions
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Give an example of a metal which:
(a) is a liquid at room temperature.
(b) can be easily cut with a knife.
(c) is the best conductor of heat.
(d) is a poor conductor of heat.Explain the meanings of malleable and ductile.
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3. Why is sodium kept immersed in kerosene oil?
4. Write equations for the reactions of:
(a) Iron with steam
(b) Calcium and potassium with water
Samples of four metals A, B, C, and D were taken. The following observations were made:
(a) A reacts with cold water.
(b) B reacts with hot water.
(c) C reacts with steam.
(d) D does not react with water or steam.
Which metal is most reactive and which is least reactive?What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
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7. (a) Write the electron dot structure for sodium, oxygen, and magnesium.
(b) Show the formation of Na₂O and MgO by the transfer of electrons.
(c) What are the ions present in these compounds?
- Why do ionic compounds have high melting points?
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9. Define the following terms:
(a) Mineral
(b) Ore
(c) Gangue
Name two metals that are found in nature in the free state. Name two metals that are found in the combined state.
What chemical process is used for obtaining a metal from its oxide?
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12. Metallic oxides of zinc, magnesium, and copper were heated with the following metals:
(a) Zinc
(b) Magnesium
(c) Copper
In which cases will you find displacement reactions taking place?
Which metals do not corrode easily?
What are alloys?
Exercise Questions
Page 56-57:
Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl₂ solution and aluminium metal
(c) FeSO₄ solution and silver metal
(d) AgNO₃ solution and copper metalWhich of the following methods is suitable for preventing an iron frying pan from rusting?
(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) All of the aboveAn element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be:
(a) Calcium
(b) Carbon
(c) Silicon
(d) IronFood cans are coated with tin and not with zinc because:
(a) Zinc is costlier than tin.
(b) Zinc has a higher melting point than tin.
(c) Zinc is more reactive than tin.
(d) Zinc is less reactive than tin.You are given a hammer, a battery, a bulb, wires, and a switch.
(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.What are amphoteric oxides? Give two examples of amphoteric oxides.
Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
In the electrolytic refining of a metal M:
(a) What would you take as the anode, the cathode, and the electrolyte?
(b) Draw a neat and well-labeled diagram of the electrolytic cell used for this purpose.Pratyush took a solution of copper sulphate in a beaker and dipped an iron nail into it. He observed that the blue colour of the solution became lighter and a brown deposit was formed on the iron nail.
(a) State the reason for the colour change.
(b) Write the chemical equation for the reaction.State two ways to prevent the rusting of iron.
What type of oxides are formed when non-metals combine with oxygen?
Give reasons:
(a) Platinum, gold, and silver are used to make jewellery.
(b) Sodium, potassium, and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
Differentiate between metals and non-metals based on their properties.
What are alloys? How are they made? List two alloys and their uses.
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