Chemistry of Metals and Alloys

Zinc chloride is a reactive salt that can undergo displacement reactions with more reactive metals. Aluminum is more reactive than zinc, so it will displace zinc from the solution, causing the vessel to corrode.

Gun metal is a type of bronze, which is an alloy primarily consisting of copper (Cu), tin (Sn), and zinc (Zn).

Air is a homogeneous mixture of various gases, primarily nitrogen and oxygen, rather than a chemical compound or a single solution.

Blister copper is impure copper

Emeralds are a variety of the mineral beryl. Beryl is a mineral composed of beryllium aluminium cyclosilicate.

An alloy is a metallic substance composed of two or more elements, where at least one is a metal. This is a standard definition in materials science.

Sharagani and Jeetal were made of silver and copper. These are some of the manuscripts made with metals like silver and copper. 

Iron was not used by Harappans. Distinctive seals were used among other applications, perhaps for identification of property and shipment of goods. Although copper and bronze were in use, iron was not yet employed.  

This is the correct option. Iron objects are coated with nickel to give them a shining appearance.

Palladium has the lowest melting point and it is the least dense so it is used in aircrafts. 

The ability to emit light at lower energy levels is due to the valence of the electrons and that is where tungsten and its physical and atomic properties come into play for lighting. 

Their attenuation is dependent upon the density of the shielding material; it can be shown that a dense shield material with a higher atomic number is a better attenuator of X-rays. Lead enjoys the advantage of being the densest of any commonly available material. Where space is at a premium and radiation protection is important, lead is often preferred. It is recognised that lead is not the densest element (e.g. tantalum, tungsten and thorium are higher on the density scale), but lead is readily available, easily fabricated and the cheapest of these materials.

Earth’s crust is the major source of metals.

The inner core of the Earth, its innermost hottest part as detected by seismological studies, is a primarily solid ball. It is believed to consist of an iron-nickel alloy, and may have a temperature similar to the Sun's surface.

Brass is an alloy of copper and zinc, while bronze is an alloy of copper and tin. Copper is the common element in both.