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CBSE Class 10 - Metals and Non-Metals - Questions and Answers

Materials: Metals and Non-metals True False
Q1: Name the metal which has highest melting point.

Answer: Tungsten is the metal which has highest melting point.

Q2: What is the composition of aqua regia?

Answer: Aqua regia is a freshly prepared mixture of concentrated hydrochloric acid [Conc. HCl] and concentrated nitric acid [Conc. HNO3] in the ratio of 3:1.

Q3: Why food cans are coated with tin not with zinc?

Answer: Food cans are coated with tin not with zinc because zinc is more reactive than tin, and zinc could react with food material and make it contaminated or spoiled.

Q4: Write the chemical characteristic of metal?

Answer: Metals have one to three valance electron in their outermost orbit, which they can loose during a chemical reaction.

Q5: A metal reacted with a dil. H2SO4, which gas would be produced?

Answer: Hydrogen gas [H2].

Q6: What is the most mellable metal?

Answer: Gold is the most mellable metal.

Q7: Why sodium and potassium are stored in kerosene?

Answer: Sodium and Potassium are stored in kerosene because they react vigorously when they are kept in open or kept in water [hot or cold] and produce H2 gas and extreme amount of heat, so they catches fire very easily in the atmosphere.

Q8: What are Amphoteric oxides? Give two examples of Amphoteric oxides.?

Answer: Metal oxides , which react with both acids and bases to form salt and water is called Amphoteric oxides.
Examples are ZnO and Al2O3 .

Q9:Name two metals, which will displace hydrogen from dilute acids, and two metals which will not.?

Answer: 1. High reactive metals such as Zn and Mg displace hydrogen from dilute acids.
2.Less reactive metals such as Cu, Ag do not displace hydrogen from dilute acids

Q10: State two ways to prevent the rusting of iron.?

Answer: 1. By coating the surface of iron by paints.
2. By preventing contact of iron surface from moist air.



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Q11: State which of the following metals would give hydrogen when added to dilute hydrochloric acid. ?
A. Fe
B. Cu
C. Mg

Answer:B. Cu (Copper does not react with dilute hydrochloric acid)

Q12:Name a non-metallic element, which conducts electricity.

Answer:Carbon in the form of graphite conducts electricity because they have 01 free electron in their three layered lattice structure.

Q13:Name two metals,Which metals do not corrode easily?

Answer: Gold (Au) & Platinum(Pt)

Q14: What are alloys?

Answer: Alloy is a homogeneous mixture of two or more metals, or a metal and a non-metal.

Q15: Define the following terms.
(i) Minerals
(ii) Ores
(iii) Gangue

Answer: i) Minerals are coumpounds or elements found in earth crust.
ii) Ores are the minerals from which metals are extracted economically.
iii) Impurities present with ore is called gangue.

Q16: Name two metals that are found in nature in the free state.

Answer: Gold [Au] and Platinum [Pt]

Q17: Name two metals that are found in nature in the combined state.

Answer: Iron [Fe] and Zinc [Zn]

Q18: Name one metals that are found in nature in the free as well as combined state.

Answer: Copper [Cu]

Q19: Name two metals, which can form hydrides with metals.

Answer: Sodium and Calcium form hydrides when react with hydrogen.

Q20: Does every mineral have a definite and a fixed composition?

Answer: Yes, mineral have a definite and a fixed composition.



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Q21: Explain the meaning of malleable and ductile.

Answer: Malleable means metal can be converted into thin sheet, ductile means metal can be drawn into thin wire.

Q22: Give an example of a metal which
i. is a liquid at room temperature.
ii. can be easily cut with a knife.
iii. is the best conductor of heat.
iv. is a poor conductor of heat.

Answer: i) Mercury [Hg]
ii) Potassium [K]
iii) Silver [Ag]
iv) Lead [Pb]

Q23: Why do ionic compounds have high melting points?

Answer: Ionic compounds are made up of positive and negative ions, which hold each other with a high electrostatic froce. That's why ionic compounds have high melting points.

Q24: Write equations for the reactions of
(i) iron with water
(ii) calcium and potassium with water

Answer:

i)

ii)

iii)

Q25: What would you observe when zinc is added to a iron(II) sulphate?

Answer: When zinc is added to iron(II) sulphate, displacement reaction takes place and forms zinc sulphate and remove iron from its coumpond. The colour of iron(II) sulphate is pale green which becomes colourless after reaction.
Zn + FeSO4 [pale green] → ZnSO4 [colourless] + Fe

Q26: Why do some metals like, Na, K, Ca, Mg not occur in nature as free state?

Answer: Metals like Na, K, Ca, Mg are more reactive in nature, hence they are not found in free state.

Q27: Name the metal which is commonly used in thermit welding?

Answer: Aluminum and Iron powder are used in thermit welding.

Q28: What is the nature of Zinc oxide?

Answer: Zinc oxide is basic in nature.

Q29: Write a chemical equation for the reaction taking place between magnesium and water using symbols.

Answer: Magnesium reacts with water to form magnesium hydroxide and hydrogen gas.
Mg + H2O -> Mg(OH)2 + H2

Q30: Aluminum is used for making cooking utensils. Which of the following properties of aluminum are responsible for the same?
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iii) Ductility
(iv) High melting point

Answer: (i) and (iv)

Q31: Which of the following is the correct arrange-ment of the given metals in ascending order of their reactivity?
Zinc, Iron, Magnesium, Sodium

Answer: Sodium > Magnesium > Zinc > Iron

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