Chemistry of Metals and Alloys

A calorimeter is typically made of copper because it has a low specific heat capacity, which allows it to reach thermal equilibrium quickly with the substance being tested.

Potassium (K) is an alkali metal that is very soft and can be easily cut with a knife. Aluminum, calcium, and iron are much harder metals.

German silver (also called nickel silver) is primarily an alloy of copper (50-70%), nickel (10-30%), and zinc (10-35%). Despite its name, it contains no actual silver. The copper is the base metal, making option B the best answer among the choices.

Punch-marked coins, the earliest currency in India, were primarily manufactured using silver and copper. These metals were easily stamped with symbols.

Lithium is the lightest metal in the periodic table, with an atomic number of 3 and a very low density. Other metals like aluminium, copper, and magnesium have significantly higher densities.

Silver is the best reflector of visible light among all metals, which is why it is commonly used to coat the back of glass mirrors.

Carbon is commonly used as a reducing agent in the extraction of metals like zinc from their oxides, as it is cheaper and effectively removes oxygen.

The Earth's crust is the primary source for most metals, which are extracted from minerals and ores found within it.

Noble metals like gold, silver, and copper are chemically unreactive and can be found in their native or free state in nature.

Due to their high reactivity, most metals readily react with other elements in nature and are therefore found as compounds (oxides, sulfides, carbonates, etc.).

Highly reactive metals like potassium, sodium, and calcium are never found in their free state; they are always found as compounds.

Metals above copper in the reactivity series are sufficiently reactive to form stable compounds with oxygen, sulfur, or carbon in nature.

Minerals are naturally occurring inorganic substances found in the Earth's crust from which metals can be extracted.

Barium sulfate is used as a radiocontrast agent in X-ray imaging of the digestive tract because it is opaque to X-rays and insoluble.

Carbon, aluminium, and sodium are all strong reducing agents used in metallurgy. Iron is generally not used as a reducing agent for these oxides, as it is less reactive than the others.