Chemistry of Metals and Alloys

Gold is not used for electrical wiring because of its high cost.

Iron was the first metal used by Vedic people, marking the beginning of the Iron Age in ancient India around 1200 BCE. While copper and gold were known earlier, iron technology revolutionized tools and weapons. Silver came later in the historical timeline.

Sodium is a soft metal, and hence can be easily cut with a knife.

Phosphorus is a non-metal.

Sulphur is the most brittle metal.

Brass is an alloy. Hence, it is not in its pure form.

The elements which show some properties of metals as well as non-metals are known as metalloids. Silicon and arsenic are metalloids.

Sodium is a highly reactive metal and occurs in the form of its compound in the earth's crust. Thus, it cannot occur in its native form.

Gold is a highly unreactive metal and thus good for making jewellery.

Diamond, a form of carbon, is the hardest known substance.

Yes, all have no unpaired electrons, hence all are colourless.

Yes, the substances which are strongly attracted by magnetic field and show permanent magnetism even in the absence of a magnetic field are ferromagnetic. For example: Fe, Co, Ni, etc.

Bronze is made up of alloys of coppers and tin

Lithium is the lightest metal with an atomic number of 3 and atomic weight of approximately 6.94. It's an alkali metal that floats on water and is less dense than any other metal. The other options are incorrect: chromium is a transition metal, bromine is a liquid nonmetal (not a metal at all), and zinc is a transition metal - all are significantly heavier than lithium.

Mercury is the only metal that is liquid at room temperature. Bromine is also liquid at room temperature, but it is a non-metal (halogen), not a metal. Hydrogen is a gas, and aluminum is a solid metal.