Chemistry of Metals and Alloys

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.

null

Nichrome (nickel-chromium alloy) is the standard material for heating elements because it has high electrical resistance, can withstand temperatures over 1000°C without oxidizing, and maintains structural integrity when heated repeatedly. Tungsten has a very high melting point but is used in incandescent bulb filaments, not heating elements. Pure iron would oxidize and rust quickly at high temperatures. Chromium alone is not used for heating elements - it's the chromium in nichrome that provides corrosion resistance.

Metals are good conductors of heat and electricity.

Mercury is in a liquid state at room temperature. 

Sodium is a soft metal, and it can be easily bent with a knife.

Iron forms a part of haemoglobin of blood.

Copper was the first metal used by humans, dating back to around 8000 BCE during the Chalcolithic period (Copper Age). Its natural occurrence in native form, malleability, and lower melting point compared to other metals made it ideal for early tool-making and ornamental purposes before bronze and iron discovery.

The Harappans used gold, copper, silver, and bronze extensively. However, they did not use iron, as iron technology came to India after the decline of the Indus Valley Civilization with the advent of the later Vedic period and the Iron Age around 1200 BCE. The Harappan civilization was primarily a Bronze Age civilization.

M may be Mg or Li, so this option is correct.

As oxygen is a gas and gases are highly compressible in nature.

Germanium is a metalloid.

The metals which are found in free state in nature are silver, gold and platinum.

Hydrogen is a non-metal with atomic number one.

Bronze is an alloy consisting primarily of copper and the addition of other metals (usually tin) and sometimes arsenic, phosphorus, aluminium, manganese and silicon.