Metallurgical Processes

Galvanization is the process of applying a protective zinc coating to iron or steel to prevent rusting. Zinc acts as a sacrificial anode, corroding preferentially to protect the underlying metal even if the coating is scratched. Tin and aluminium provide barrier protection only, while gallium is not used for galvanization.

this option is correct because Ma comes higher than Boron and silicon in the electrochemical series hence can be used as a reducing agent in the metallurgy of boron and silicon.

This option is correct because silver obtained from argintiferous lead still contains lead impurities. Thus, the lead is removed by silver.

Electroplating is the process of using an electric current to deposit a thin layer of metal onto the surface of another object. This is commonly done to improve corrosion resistance, enhance appearance, or increase surface hardness.

Laterite soil is formed through the process of intense leaching, where heavy rainfall washes away silica and lime, leaving behind iron and aluminum oxides. This process occurs in tropical climates with alternating wet and dry seasons.

Due to very high melting point of tungsten it can withstand very high temperature inside the bulb without burning. So filament of the bulb is made of tungsten.

In a period, as we proceed from left to right, the metallic character of elements decreases. This is due to decrease in size and increase in the s- character.

Down's process is the industrial method used for the production of sodium metal by the electrolysis of molten sodium chloride. The other processes listed are used for different chemical extractions.

1. The floatation process is the concentration method of sulphide ores. Zinc ores mainly ZnS are concentrated by floatation method, then roasted in air to give ZnO and SO₂.
   1. Zn is used extensively for coating for the appliances made up of corrosive metals like Fe to prevent them from rusting.
   2. Cd metal absorbs neutrons very well, and is used to make control rods in nuclear reactors.
   3. The largest use of mercury is in electrolytic cells for the production of sodium hydroxide and chlorine gas at commercial level.

This option is correct, because this process is for electrolytic refining of Al. The electrolytic cell consists of three liquid layers of different gravities. The top layer of pure Al acts as cathode. The bottom layer; molten impure Al acts as anode. The middle layer is fused cryolite and barium fluoride. It acts as an electrolyte. When current flows, Al ions from the middle layer are discharged at the cathode.

Stainless steel is an alloy of iron containing chromium, which creates a thin, protective layer of oxide on the surface. This layer prevents the iron from reacting with oxygen and water, thereby resisting rust and corrosion.

Chrome steel is known for its hardness and high tensile strength, which are essential for manufacturing durable tools and springs. While it is used in automotive parts, it is specifically valued for its resilience in tool making.

Both these changes can be controlled. Rusting of iron happens over a long period of time and if treated right it can be prevented. Similarly milk can be prevented from spoiling by turning into curd or by boiling and pasteurization.

P. Due to non-availability of d orbitals, boron is unable to expand its octet. Therefore, the maximum covalence of boron cannot exceed 4. Al, Ga, In and Tl have vacant d orbitals and form such type of ions. Q. Alclad is a trademark of Alcoa used as a generic term to describe corrosion-resistant aluminium sheet formed from high-purity aluminium surface layers metallurgically bonded to high-strength aluminium alloy core material. R. Boron fiber exhibits a unique combination of high strength, high modulus and large diameter. Boron fibres are used in making bullet-proof vest and light composite material for aircraft.

Rusting is a chemical process where iron reacts with oxygen and moisture to form iron oxide, which is an oxidation reaction.