Metals, Minerals, Ores : Properties, Uses Part-1

Metal is obtained at high temperature by the reduction of ore in the process of smelting. The metal is obtained in a fused state in this process.

Calcium is a dull, grey, solid element with a silver appearance which exists in the solid state. It has a high melting point (1115K) and boiling point (1757K). All these features make it related to the metals. The valence electron configuration of Calcium is 2,8,8,2. Hence, it has a tendency to lose two electrons to get a noble gas configuration. Since it can lose electrons, it can be used in ionic bonding and can form ionic compounds. Like other metals, Calcium also reacts vigorously with dilute acids like hydrochloric acid and produces large amounts of heat, forms Calcium Chloride (CaCl₂) and Hydrogen gas. All these properties of Calcium prove that it is a metal.

Among the given options, Potassium is the most reactive metal. The given metals in order of reactivity are: Potassium (K) > Sodium (Na) > Calcium (Ca) > Iron (Fe).

From the above-mentioned data, it is clear that Lithium is the lightest and Osmium is the heaviest metal.

Among all natural materials, diamond is the hardest (which is non-metal) whereas, among the metals, Tungsten is the hardest.

Diamond is the hardest, least compressible, and best thermal conductor among all natural materials.

Diamond is the hardest naturally occurring substance present on the Earth. However, wurtzite boron nitride is believed to be harder than diamond. It has a similar structure to diamond but is made up of different atoms. It is formed during volcanic eruptions with high temperature and pressure The simulations showed that wurtzite boron nitride could handle 18% more stress than diamond, which is due to the re-orientation of the flexible bonds and the more complex structure than diamonds. But because only minute amounts of this mineral have been discovered, its hardness properties are yet to be experimentally tested. That's why UPPSC experts had answered option (d) for this question in their official answer key.