(1)

Ductility is the property which allows metals to be drawn into thin wires.

(2)

Ionic compounds conduct electricity in aqueous solution or molten state. In solid state, they are non-conductors of electricity because of the absence of free ions.

(4)

Good thermal conductivity and high melting point of aluminium are the properties that make it suitable for making cooking utensils.

(2)

When zinc metal is put in the solution of copper sulphate, zinc displaces copper from its solution and forms zinc sulphate. This is because zinc is above copper in the reactivity series and is more reactive. The blue colour of the solution becomes colourless when zinc is added.

(3)

On prolonged exposure to air, silver metal reacts with hydrogen sulphide gas and forms a coating of silver sulphide $\left(A{g}_{2}S\right)$. Due to this, silver loses its shine, turns black, and gets tarnished.

(4)

Except mercury, all metals are solid at room temperature. Mercury is the only metal that exists in liquid state at room temperature.

(2)

Aqua regia is a mixture of three parts concentrated HCl and one part concentrated $HN{O}_3$ (3:1). Gold (Au) is a noble metal that does not dissolve in dilute acids but dissolves in aqua regia. Hence, the metal in test tube C is gold.

(3)

Suspensions and colloids are heterogeneous mixtures, whereas an alloy is a homogeneous mixture of two or more metals. The properties of a metal can be improved by mixing it with another metal. metal such as melting point, electrical conductivity, resistant to corrosion and strong metals. Example of alloys are stainless steel (homogeneous mixture of Fe, Cr, Ni), brass (homogeneous mixture of Cu and Zn), bronze (homogeneous mixture of Cu and Sn) etc.

(2)

Element A is sodium as it is soft and can be cut with knife. It is kept in kerosene because it reacts vigorously when comes in contact with water or air.

(2)

Reaction between compound X and Y forms compound Z. In the reaction, X loses electron and Y gains electron which means compound Z is a crystalline solid as ionic or electrovalent bond is formed between X and Y. As compound Z is a crystalline solid, it has high melting point and it conducts electricity in the molten state. Thus, the property not shown by Z is that it has low melting point.

(4)

Electronic configuration of X is 2, 8 = 10 (it is same as the electronic configuration of Neon) Thus, element X is a noble gas element.

Electronic configuration of Y is 2, 8, 7 = 17 (It is same as the electronic configuration of chlorine atom which belongs to halogen family and is a non-metal). Thus, element Y is a non-metal.

(4)

Calcium metal reacts less violently with water. It produces a hydroxide known as calcium hydroxide (a cloudy white precipitate), and bubbles of hydrogen gas are produced.
The hydrogen gas thus produced sticks to the surface of calcium due to which it floats over the water surface.

$Ca\left(s\right) + 2H_{2}O\left(l\right)\to Ca{\left(OH\right)}_2\left(aq\right)+H2\uparrow$
                                      Calcium hydroxide

very less amount of heat is produced in this reaction due to which hydrogen gas formed does not catch fire.

(3)

The electrical characteristics such as electrical insulating properties or dielectric constant of PVC (polyvinyl chloride) are high due to which it is used as an insulating material. To prevent any accidental contact with other conductors, the metallic part of an electrical wire are covered with PVC.

(3)

Metals are good conductors of electricity. Metals are sonorous in nature which means on striking them they make a ringing sound.
Metals are lustrous which means they have shiny appearance. Metals are ductile which means they can be drawn into long thin wires. Hence, the property not shown by metals is dullness.

(2)

$C{u}^{2+}$ion travels towards the negative terminal, i.e. iron plate, and deposits on it because it is positively charged. As a result, the iron plate is copper-plated. Since copper atoms enter the solution from the positive terminal, i.e., the copper plate, there is no shortage of copper atoms.

(2)

Ductility is the property by which metals can be drawn into long thin wires without breaking. Gold, silver and platinum are often drawn into long stands for use in jewellery. However, gold has a significantly greater ductility than platinum and it is considered as the earth’s most ductile metals as one ounce of gold could be drawn to a length of 50 miles.

(1)

Non-metals react with oxygen to form non-metallic oxide. Non-metallic oxide such as sulphur dioxide and nitrogen dioxide present in air are responsible for acid rain as they react with the moisture present in air and forms the acidic compounds.

(2)

Oxides of metals are basic in nature because they react with water to form metal hydroxides which are alkaline in nature. These metal hydroxides when dissolved in water release $O{H}^{-}$ ions in solution which will turn red litmus solution to blue. Therefore, non-metallic oxides are acidic in nature.

(3)

Food cans are coated with tin and not with zinc because zinc is above the tin in the reactive series and can react with the food items and alter their taste. Hence, due to this reason food cans are coated with tin and not with zinc.

(2)

Silver (Ag) metal would be displaced from the solution of its salts by other three metals because silver is less reactive than magnesium (Mg), zinc (Zn) and copper (Cu).

(2)

In the reactivity series, aluminium is above zinc, iron and copper, which makes it more reactive than these elements. Mrignayni would observe that out of the four solutions, reaction will take place in solution B, C and D. The reactions are as follows:

In Solution B: Aluminium will displace iron from ferrous sulphate solution to form aluminium sulphate and iron is precipitated.

$2FeS{O}_4 \left(aq\right) + 2Al \left(s\right) \to A{l}_2{\left(S{O}_4\right)}_3 \left(aq\right) + 3Fe \left(s\right)$

In Solution C: Aluminium will displace zinc from zinc sulphate solution to form aluminium sulphate and zinc is precipitated.

$2Al \left(s\right) + 3ZnSO₄ \left(aq\right) \to Al₂(SO₄)₃ \left(aq\right) + 3Zn \left(s\right)$

In Solution D: Aluminium will displace copper from copper sulphate solution to form aluminium sulphate and copper is precipitated.

$2Al \left(s\right) + 3CuSO₄ \left(aq\right) \to Al₂(SO₄)₃ \left(aq\right) + 3Cu \left(s\right)$

(3)

Steel is an alloy which contains iron as a metal and carbon as a non-metal.

(2)

The elements or compounds which occur naturally in the earth crust are known as minerals. The mineral from which an element can be extracted easily and profitably is called an ore. The impurities or unwanted substances present in ore such as sand, rock etc. is known as gangue.