3. Metals and Non-metals

SEBA Class 10 Science Chapter 3 Metals and Non-metals

Chapter 3 Metals and Non-metals

SEBA Chapter 3 Metals and Non-metals Multiple Choice Questions and Answers :

Question : Choose the metalloid from amongst the following elements : [SEBA 2015]

(a) Sodium (b) Aluminium (c) Chlorine (d) Boron

Answer : (D) Boron

Question : Which of the following metals reacts violently with cold water ? [SEBA 2016]

(a) Al (b) Fe (c) Na (d) Ca

Answer : (c) Na

Question : Which of the following metals react vigorously with oxygen ?

(a) Na (b) Fe (c) Cu (d) Ag

Answer : (a) Na

[Sodium (Na) is a metal that reacts vigorously with oxygen. When sodium comes into contact with oxygen, it undergoes a rapid and exothermic reaction, forming sodium oxide () . ]

Question : When iron is mixed with nickel and chromium , we get an alloy named . [2023]

Answer : Stainless steel .

[When iron is mixed with nickel and chromium, we get an alloy named stainless steel.]

Question : 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 metal.
Answer: (d) solution and copper metal.

Question : Which of the following methods is suitable for preventing an iron frying pan from rusting? [SEBA 2020]
(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) All of the above.

Answer: (c) Applying a coating of zinc
Question : An 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 [SEBA 2017,2021]
(a) calcium
(b) carbon
(c) silicon
(d) iron.

Answer: (a) Calcium .
Question : Food cans are coated with tin and not with zinc because [SEBA 2018]
(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.
Answer: (c) zinc is more reactive than tin.

Question : Which of the following property is generally not shown by metals?

(a) Electrical conduction

(b) Sonorous in nature

(d) Ductility

Answer : (c) Dullness

Question : The ability of metals to be drawn into thin wire is known as

(a) ductility

(b) malleability

(d) conductivity

Answer : (a) ductility

Question : Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?

(i) Good thermal conductivity

(ii) Good electrical conductivity

(iii) Ductility

(iv) High melting point

(a) (i) and (ii) (b) (i) and (iii)

Answer : (a) (i) and (ii)

Good thermal conductivity and good electrical conductivity.

[ (i) Good Thermal Conductivity: Aluminium's high thermal conductivity allows for efficient heat transfer, ensuring that the cooking utensil heats up quickly and distributes heat evenly. This property is crucial for cooking various dishes.

(ii) Good Electrical Conductivity: While electrical conductivity is not the primary reason for using aluminium in cooking utensils, it can be relevant for certain applications, such as electric stovetops or pans used in induction cooking. The electrical conductivity of aluminium makes it suitable for these purposes ]

Question : Which one of the following metals do not react with cold as well as hot water?

(a) Na

(b) Ca

(d) Fe

Answer : (d) Fe (Iron).

[ Iron (Fe) does not react with cold or hot water. While it can react with steam to form iron oxide and hydrogen gas ]

Question : Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

(a) FeO

(b)

(c)

(d) and

Answer : (c)

[ The reaction is ]

Question : What happens when calcium is treated with water?

(i) It does not react with water

(ii) It reacts violently with water

(iii) It reacts less violently with water

(iv) Bubbles of hydrogen gas formed stick to the surface of calcium

(a) (i) and (iv) (b) (ii) and (iii)

Answer : (d) (iii) and (iv).

[ When calcium is treated with water, it reacts to produce calcium hydroxide and hydrogen gas.

The reaction is ]

Question : Generally metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)?

(a)

(b) HCl

(c)

(d) All of these

Answer : (c)

[Nitric acid is a strong oxidizing agent, and when it reacts with metals, it tends to oxidize them and itself undergoes reduction, resulting in the formation of nitrogen oxides and not hydrogen gas. ]

Question : The composition of aqua-regia is

(a) Dil.HCl : Conc.

3 : 1

(b) Conc.HCl : Dil.

3 : 1

(d) Dil.HCl : Dil.

3 : 1

Answer : (c) Conc.HCl : Conc.

3 : 1

Question : Which of the following are not ionic compounds?

(i) KCl

(ii) HCl

(iii)

(iv) NaCl

(a) (i) and (ii) (b) (ii) and (iii)

Answer : (b) (ii) and (iii).

[ HCl (hydrochloric acid) is a covalent compound, not an ionic compound. It is formed by the combination of hydrogen (a non-metal) and chlorine (a non-metal).

(carbon tetrachloride) is also a covalent compound. It consists of carbon (a non-metal) and four chlorine atoms (non-metals) bonded covalently. ]

Question : Which one of the following properties is not generally exhibited by ionic compounds?

(a) Solubility in water

(b) Electrical conductivity in solid state

(d) Electrical conductivity in molten state

Answer : (b) Electrical conductivity in solid state

[ Ionic compounds exhibit electrical conductivity in the molten state or in aqueous solutions.]

Question : Which of the following metals exist in their native state in nature?

(i) Cu

(ii) Au

(iii) Zn

(iv) Ag

(a) (i) and (ii) (b) (ii) and (iii)

Answer : (c) (ii) and (iv)

[ Gold , silver , platinum … etc are found in the free state . ]

Question : Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?

(i) Au

(ii) Cu

(iii) Na

(iv) K

(a) (i) and (ii) (b) (i) and (iii)

Answer : (a) (i) and (ii):

[ Gold (Au) and copper (Cu) are both refined by electrolytic refining, a process that involves passing an electric current through a solution containing ions of the metal to be refined, and the metal is deposited at the cathode. ]

Question : Silver articles become black on prolonged exposure to air. This is due to the formation of

(a)

(b)

(c)

(d) and

Answer : (c)

[ The blackening of silver articles on prolonged exposure to air is due to the formation of a thin layer of silver sulfide (). ]

Question : Galvanisation is a method of protecting iron from rusting by coating with a thin layer of

(a) Gallium

(b) Aluminium

(d) Silver

Answer : (c) Zinc

[Galvanization is a method of protecting iron from rusting by coating it with a thin layer of zinc. ]

Question : Stainless steel is very useful material for our life. In stainless steel, iron is mixed with

(a) Ni and Cr

(b) Cu and Cr

(d) Cu and Au

Answer : (a) Ni and Cr

[ In stainless steel, iron is mixed with (a) Ni (Nickel) and Cr (Chromium). ]

Question : If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

(a)

(b)

(c)

(d) CuO

Answer : (d) CuO

[ If copper is exposed to air, it reacts with oxygen and moisture to form copper oxide. The green coating that forms on the surface of copper is primarily composed of copper(II) oxide (CuO). ]

Question : Generally, metals are solid in nature. Which one of the following metals is found in liquid state at room temperature?

(a) Na

(b) Fe

(d) Hg

Answer : (d) Hg

[ The metal that is found in a liquid state at room temperature is mercury (Hg). ]

Question : Which of the following metals are obtained by electrolysis of their chlorides in molten state ?

(i) Na

(ii) Ca

(iii) Fe

(iv) Cu

(a) (i) and (iv) (b) (iii) and (iv)

Answer : (d) (i) and (ii)

[ The metals obtained by electrolysis of their chlorides in molten state are sodium (Na) and calcium (Ca). ]

Question : Generally, non-metals are not lustrous. Which of the following non- metal is lustrous?

(a) Sulphur

(b) Oxygen

(d) Iodine

Answer : (d) Iodine

[ Iodine is a non-metal that is lustrous. Iodine has a shiny appearance, especially when it is in the form of crystals. ]

Question : Which one of the following four metals would be displaced from the solution of its salts by other three metals?

(a) Mg

(b) Ag

(d) Cu

Answer : (b) Ag (Silver).

[ Silver is less reactive than magnesium (Mg), zinc (Zn), and copper (Cu). Therefore, magnesium, zinc, and copper can displace silver from the solution of its salts.]

Question : 2 mL each of concentrated HCl, and a mixture of concentrated HCl and concentrated in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put ineach test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be

(a) Al

(b) Au

(d) Pt

Answer : (b) Au.

[ Aqua regia is known for its ability to dissolve noble metals like gold (Au) and platinum (Pt). Gold (Au) is a noble metal that can be dissolved by aqua regia. ]

Question : An alloy is

(a) an element

(b) a compound

(d) a heterogeneous mixture

Answer : (c) homogeneous mixture.

[ An alloy is a mixture of two or more elements, at least one of which is a metal. ]

Question : An electrolytic cell consists of

(i) positively charged cathode

(ii) negatively charged anode

(iii) positively charged anode

(iv) negatively charged cathode

(a) (i) and (ii) (b) (iii) and (iv)

Answer : (b) (iii) and (iv)

[ In an electrolytic cell: The cathode is negatively charged and the anode is positively charged. ]

Question : During electrolytic refining of zinc, it gets

(a) deposited on cathode

(b) deposited on anode

(d) remains in the solution

Answer : (a) deposited on cathode

[ During the electrolytic refining of zinc, zinc is deposited on the cathode. ]

Question : An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following

(a) Mg

(b) Na

(d) Ca

Answer : (b) Na

[ The element described as soft, reacting vigorously with water, and being very reactive to air is most likely sodium (Na). ]

Question : Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?

(a) Brass

(b) Bronze

(d) Steel

Answer : (d) Steel

[ Steel is an alloy of iron (a metal) and carbon (a non-metal). Therefore, steel is the alloy that contains a non-metal as one of its constituents. ]

Question : Which among the following statements is incorrect for magnesium metal?

(a) It burns in oxygen with a dazzling white flame

(b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas

(d) It reacts with steam to form magnesium hydroxide and evolves hydrogen gas

Answer : (b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas.

[ Magnesium does not react vigorously with cold water. Instead, it reacts slowly with hot water or steam to form magnesium oxide and evolves hydrogen gas. ]

Question : Which among the following alloys contain mercury as one of its constituents?

(a) Stainless steel

(b) Alnico

(d) Zinc amalgam

Answer : (d) Zinc amalgam

[ The alloy that contains mercury as one of its constituents is zinc amalgam .]

Question : Reaction between X and Y, forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z?

(a) Has high melting point

(b) Has low melting point

(d) Occurs as solid

Answer : (b) Has low melting point

[ Ionic compounds typically have high melting and boiling points due to the strong electrostatic forces between oppositely charged ions. Therefore, the property not shown by Z would be having a low melting point. Ionic compounds tend to be solids at room temperature with high melting points.]

Question : The electronic configurations of three elements X, Y and Z are X - 2, 8; Y - 2, 8, 7 and Z - 2, 8, 2. Which of the following is correct?

(a) X is a metal

(b) Y is a metal

(d) Y is a non-metal and Z is a metal

Answer : (d) Y is a non-metal and Z is a metal

[ The electronic configurations provided are:

X: 2:8 ; Y: 2.8.7 ; Z : 2.8.2

X has 2 electrons in the outermost shell, suggesting it is a metal.

Y has 7 electrons in the outermost shell, suggesting it is a non-metal.

Z has 2 electrons in the outermost shell, suggesting it is a metal. ]

Question : Although metals form basic oxides, which of the following metals form an amphoteric oxide?

(a) Na

(b) Ca

(d) Cu

Answer : (c) Al

[ An amphoteric oxide is one that can act as both an acid and a base. Among the options provided, aluminum (Al) forms an amphoteric oxide. ]

Question : Generally, non-metals are not conductors of electricity. Which of the following is a good conductor of electricity?

(a) Diamond

(b) Graphite

(d) Fullerene

Answer : (b) Graphite.

[ Graphite is a good conductor of electricity. Graphite is a form of carbon with a unique structure that allows electrons to move freely, making it a good conductor. ]

Question : Electrical wires have a coating of an insulting material. The material, generally used is

(a) Sulphur

(b) Graphite

(d) All can be used

Answer : (c) PVC

[ Electrical wires are typically coated with an insulating material to prevent the flow of electric current and to ensure the safety of the wiring. PVC (Polyvinyl chloride) is a common insulating material used for electrical wires.]

Question : Which of the following non-metals is a liquid?

(a) Carbon

(b) Bromine

(d) Sulphur

Answer : (b) Bromine.

[ Bromine is a non-metal that exists in a liquid state at room temperature. ]

Question : Which of the following can undergo a chemical reaction?

(a)

(b)

(c)

(d)

Answer : (d)

[ In this case, iron (Fe) is displacing copper (Cu) from copper sulfate () in a single displacement reaction.]