Railway Science (Chemistry-Metals , Non-Metals and Alloys) (Part-III)

Conductance refers to the ability of a material to conduct electricity. Porosity refers to the presence of small voids or holes in a material. Malleability is a property of a material by which it can be beaten to form thin sheets.

This metal is highly conductive to electricity, meaning it allows electrons to flow easily through it. Silver: While silver is even more conductive than copper, its high cost and scarcity make it impractical for widespread use in electrical wiring. Magnesium and Lead is a poor conductor of electricity.

Solder: This common type contains 60% tin and 40% lead. It offers a good balance of melting point, strength, and flowability. Important alloys and their uses: Brass (Cu + Zn) - In making utensils, Bronze (Cu + Sn) - In making coins, bell and utensils, Gun Metal (Cu + Zn + Ni) - In making guns, barrels, gears and bearings, Rolled Gold (Cu + Al) - In making cheap ornaments.

It is a highly reactive metal that reacts vigorously with air and moisture, readily undergoing oxidation and combustion. Iron: While iron oxidizes (rusts) when exposed to air and moisture, the process is relatively slow.

Sodium (Na - 11)was discovered in 1807 by the English chemist Humphry Davy from electrolysis of caustic soda (NaOH). It reacts vigorously with oxygen and moisture due to its high reactivity so keeping it in kerosene will prevent sodium from coming in contact with oxygen and moisture.

It is an alloy of mercury with one or more metals. Example - Sodium along with liquid mercury is called sodium amalgam. An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. Bronze - An alloy of copper and tin. Brass - An alloy of copper and zinc. Solder - An alloy of lead and tin.

The metals like Na (Sodium), K (Potassium), Ca (Calcium) and Mg (Magnesium) are not found in their free state in nature. Au (Gold), Pt (platinum), Cu (copper) and Ag (silver) are least reactive metals, hence they are found in the free state in nature.

(symbol W and atomic number 74). It is used in products such as x-ray tubes, light bulbs, high-speed tools, welding electrodes, turbine blades, and armor penetrators. The boiling point of tungsten is approximately 10701 °F, and the melting point is approximately 6170 °F. Electrical resistivity of Tungsten at 20°C is 5.20 × 10⁻⁸ .

It refers to the shiny appearance exhibited by metals due to their ability to reflect light. Malleability: The property of metals by which they can be beaten into thin sheets. Hardness: It refers to the ability of a material to resist deformation.

The property of metals by which they can be beaten into thin sheets is called malleability. Some other examples : Copper, Silver, Zinc, etc.