Metals and Non-Metals: Class 10 Science Q&A · Page 2
114 free answers on Metals and Non-Metals (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10CBSE
Explain the key physical differences between metals and non-metals, providing at least three distinct properties for each.
Metals are generally lustrous, malleable, ductile, good conductors of heat and electricity, and solid at room temperature (except mercury). Non-metals are typically dull, brittle, non-ductile, poor conductors of heat and electricity (except graphite), and can exist as solids, liquids, or gases at room temperature.
- ScienceClass 10CBSE
List three uses of non-metals in everyday life and explain their significance.
Oxygen: Essential for respiration in living organisms and combustion processes. Without oxygen, life as we know it would not exist, and many industrial processes like burning fuels would be impossible.Nitrogen: Used in fertilizers (e.g., urea, ammonia) for plant growth, and as an inert atmosphere in packaging food items to prevent spoilage. It is crucial for agriculture and food preservation.Chlorine: Used as a disinfectant for water
- ScienceClass 10CBSE
Why do ionic compounds have high melting and boiling points?
Ionic compounds are formed by strong electrostatic forces of attraction between oppositely charged ions. These forces are very strong and extend throughout the entire crystal lattice. A significant amount of energy is required to overcome these strong inter-ionic forces and break down the crystal structure, allowing the ions to move freely (melt) or separate completely (boil). Therefore, ionic compounds typically have high melting and boiling points.
- ScienceClass 10CBSE
Describe the method of froth flotation used for concentrating sulphide ores.
Froth flotation is a metallurgical process used for concentrating sulphide ores. The finely powdered ore is mixed with water, a frothing agent (like pine oil), and a collector (like potassium ethyl xanthate). Air is then blown into the mixture through a rotating paddle. The frothing agent creates a stable froth, and the collector
- ScienceClass 10CBSE
Explain the difference between roasting and calcination in the context of metal extraction. When is each process used?
Both roasting and calcination are processes used to convert metal ores into their oxides before reduction.Roasting: This process involves heating a sulphide ore strongly in the presence of excess air. The sulphide ore is converted into its metal oxide and sulphur dioxide gas is released. It is used for sulphide ores (e.g., 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g)).Calcination: This process involves heating a carbonate ore or hydrated oxide ore stron
- ScienceClass 10CBSE
Describe the electrolytic refining of copper. Include a labelled diagram.
Electrolytic refining is the most widely used method for refining impure metals like copper. In this process, the impure metal is made the anode, and a thin strip of pure metal is made the cathode. An aqueous solution of a salt of the metal (e.g., acidified copper sulphate for copper) is used as the electrolyte. When an electric current is pa
- ScienceClass 10CBSE
What is galvanization? How does it protect iron from rusting?
Galvanization is the process of coating iron or steel with a thin layer of zinc. It protects iron from rusting in two main ways: Barrier Protection: The zinc layer acts as a physical barrier, preventing the iron from coming into contact with oxygen and moisture. Sacrificial Protection: Zinc is more reactive than iron. If t
- ScienceClass 10CBSE
Give two chemical properties that distinguish metals from non-metals, and provide an example for each.
1. Reaction with Oxygen: Metals generally react with oxygen to form basic oxides (e.g., 2Mg(s) + O2(g) → 2MgO(s), where MgO is basic). Non-metals react with oxygen to form acidic or neutral oxides (e.g., C(s) + O2(g) → CO2(g), where CO2 is acidic).2. Reaction with Acids: Metals above hydrogen in the reactivity series react with dilute acids to produce hydrogen gas (e.g., Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)). Non-metals generally do not react
- ScienceClass 10CBSE
Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2 . What steps will you take to convert them into metals?
Soln: Ore A gives CO2 on heating hence it is a carbonate ore Steps involved in Extraction of ore A Calcination Ore is heated in limited supply of air to obtain metal oxide ACO3 AO+ CO2 Reduction Metal oxide is reduced with coke to obtain metal. AO+C A+ CO Ore B is a sulphide ore Steps involved in extraction of element B are Roasting Ore is heated in presence of air to obtain me
- ScienceClass 10CBSE
An element A burns with golden flame in air. It reacts with another element B, atomic number 17 to give a product C. An aqueous solution of product C on electrolysis gives a compound D and liberates hydrogen. Identify A, B, C and D. Also write down the equations for the reactions involved.
Soln: Element A is 17 Sodium because it will burn with golden flame in air. Element B is Chlorine for its atomic number is 17. Product C is Sodium Chloride 2Na +CL2 2NaCl Product D is Sodium hydroxide 2NaCl+ 2H2O 2NaOH+ Cl2+H2
- ScienceClass 10CBSE
Of the three metals X, Y and Z. X reacts with cold water, Y with hot water and Z with steam only. Identify X, Y and Z and also arrange them in order of increasing reactivity.
Soln: X reacts with cold water. Hence , the element should be Sodium Ca + H₂O Ca(OH)₂ + H₂ Y reacts with hotwater, Hence, it is "Magnesium" Mg + H₂O Mg(OH)₂ + H₂ Z reacts with steam only. Hence , it is Iron Fe + H₂O Fe₂O₃+ H₂ Arranging in ascending order (increasing order of reactivity) Fe < Mg < Ca
- ScienceClass 10CBSE
Explain the following (a) Reactivity of Al decreases if it is dipped in HNO3 (b) Carbon cannot reduce the oxides of Na or Mg (c) NaCl is not a conductor of electricity in solid state whereas it does conduct electricity in aqueous solution as well as in molten state (d) Iron articles are galvanised. (e) Metals like Na, K, Ca and Mg are never found in their free state in nature.
Soln: a) Reactivity of Aluminium decreases if it is dipped in HNO3 because HNO3 is a strong oxidizing Here a layer a layer of aluminium oxide gets deposited because of which reactivity of alumnium gets reduced . Carbon cannot reduce the oxides of Na or Mg because these are highly reactive Na and Mg have higher affinity to oxygen than carbon. Hence carbon fails to reduce the oxides of Na and Mg. NaCl is not a co
- ScienceClass 10CBSE
Give the steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores.
Soln: During the extraction of metals of low and medium reactivity from their respective sulphide ores. They are first heated in presence of atmospheric oxygen. This step will give out oxides of metal. This step is used as it is more efficient method to extract methods. Ex: Cinnabar is heated in air to get mercuric sulphide oxidize to produce mercuric oxide. 2HgS+3O2 2HgO+2SO2 Mercuric oxide is further heat to get Mercury 2HgO 2Hg+O2<
- ScienceClass 10CBSE
A non-metal A which is the largest constituent of air, when heated with H2 in 1:3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O2 it gives an oxide C. If this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidising agent. (a) Identify A, B, C and D (b) To which group of periodic table does this non-metal belong?
Soln: a) Non-metal a is nitrogen because it is the largest constituent of air which constitute around 78% of the gases.. B is Ammonia, C is Nitrogen-di-oxide and D is Nitric acid. When heated with H2 in 1:3 ratio in the presence of catalyst (Fe) following reaction takes place. 3N2+3H2 2NH3 On heating Nitrogen with O2 it gives nitrogen-di-oxide N2 +3O 2NO2 When nitrogen-di-oxide is passed into water
- ScienceClass 10CBSE
A solution of CuSO4 was kept in an iron pot. After few days the iron pot was found to have a number of holes in it. Explain the reason in terms of reactivity. Write the equation of the reaction involved.
Soln: Iron is more reactive than copper hence Iron displaces Copper to produce FeSO4. In this process a portion of Iron Gets dissolved which results in Holes in the pot. Fe+ CuSO4 FeSO4+ Cu
- ScienceClass 10CBSE
An element forms an oxide A2O3 which is acidic in nature. Identify A as a metal or non-metal.
Soln: A is a non-metal because oxides of non-metals are acidic in nature.
- ScienceClass 10CBSE
A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.
Soln: Copper is the metal which does not react with acids. With oxygen it forms Copper Oxide. Metal M is Copper and black colored product is Copper oxide. 2Cu+ O2 2CuO
- ScienceClass 10CBSE
A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming (a) Identify A, B and C (b) To which Group of Periodic Table does A belong?
Soln: A is B is Carbon monoxide C is Carbon-dioxide Group 14
- ScienceClass 10CBSE
What happens when (a) ZnCO3 is heated in the absence of oxygen? (b) a mixture of Cu2O and Cu2S is heated?
Soln: When ZnCO3 is heated in the absence of oxygen Zinc Oxide and Carbon-di-oxide are ZnCo3 ZNO + CO2 When a mixture of Cu2O and Cu2S is heated we get pure copper 2 Cu2O+ Cu2S6Cu+SO2
- ScienceClass 10CBSE
Give the formulae of the stable binary compounds that would be formed by the combination of following pairs of elements. (a) Mg and N2 (b) Li and O2 (c) Al and Cl2 (d) K and O2
Soln: Magnessium Nitride (Mg3N2) Lithium Oxide( Li2O) Aluminium Chloride( AlCl3) Potassium Oxide ( K2O)