Metals and Non-Metals

It is an important physical property of metals. For example, gold and silver are both malleable and ductile.

Alloys are used because they have high melting point which ensures that the heating element does not melt upon heating continuously. The element chosen as heating element should be such that it has high resistance because of Joule's law of heating:
Heat is directly proportional to resistance, i.e. more resistance more heat.

 Pitchblende is an ore of uranium.

Wood does not produce a ringing sound when struck with another material. So, it is not a sonorous material. Sonorous material produces a ringing sound when struck with another material.

Refining is the final process in metallurgy where impure metal (obtained from reduction of ore) is purified to remove residual impurities and obtain the pure metal. Different refining methods include liquation, distillation, poling, electrolytic refining, and zone refining. Roasting is an earlier process that converts sulfide ores to oxides, not a purification method. Regulating is unrelated to metallurgy.

Phosphorus (particularly white and red phosphorus) has been historically used in the match industry. White phosphorus was used in early 'strike-anywhere' matches, but it was highly toxic and dangerous due to its tendency to ignite spontaneously. Modern safety matches use red phosphorus on the striking surface, which is safer. While phosphorus is crucial in fertilizers, detergents, food additives, and metallurgy, the match industry is a classic textbook application taught in schools.

Tungsten (W) is used for electric bulb filaments because it has the highest melting point of all metals at approximately 3422°C (6192°F), allowing it to remain solid and emit light at the high temperatures (~2500°C) needed for bright illumination. It also has very low vapor pressure at high temperatures, meaning it doesn't evaporate quickly. Nichrome (nickel-chromium alloy) is used for heating elements, not light bulb filaments. Iron would melt quickly at bulb operating temperatures.

The number of non-metals varies depending on classification criteria. Some sources count 17-18 non-metals (excluding metalloids), while others count 22-23 (including certain elements). The answer of 22 is consistent with some Indian educational board classifications. Elements classified as non-metals include hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, selenium, and the halogens (F, Cl, Br, I). The noble gases are sometimes counted separately. The exact count depends on whether metalloids like boron, silicon, and germanium are included.

Aluminium foil is used to make medicine wrappers because it is malleable.

Silver has the highest electrical conductivity of all metals, approximately 6.30×10^7 S/m at room temperature. This means it allows electric current to pass through it with the least resistance. Gold and copper are also excellent conductors, but silver outperforms all metals in conductivity.

Gangue is the term used in metallurgy to describe the worthless material (sand, clay, rock, limestone, mica) that surrounds or is mixed with the mineral ore. During ore processing, gangue is separated from the valuable ore through various beneficiation processes like crushing, grinding, and flotation.

 Antimony is used in fireworks.

Tin is less reactive than zinc and forms a protective oxide layer that prevents food contamination. Zinc is more electropositive in the reactivity series, so it would react more readily with acidic food contents, potentially contaminating the food and compromising the can. Tin's lower reactivity makes it ideal for food container lining.

Hydrogen is used in the hydrogenation of vegetable oils to make vegetable ghee. 

Sodium has low melting and boiling points.

Iodine is the only non-metal which is lustrous.

Car batteries are lead-acid batteries, using lead dioxide as the positive plate and sponge lead as the negative plate, with sulfuric acid as the electrolyte. The lead-acid chemistry provides the high current needed for engine starting and the rechargeability required for automotive use. This technology has been the standard for over 100 years.

Graphite is a non-metal which conducts electricity. Because of this reason, a graphite is used in electrodes of a dry cell.