Chemistry of Metals and Alloys

It is in liquid form which does not make a group with the other four options.

The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds.These carbides have metallic properties and are refractory. Some exhibit a range of stoichiometries, e.g. titanium carbide, TiC. Titanium carbide and tungsten carbide are important industrially and are used to coat metals in cutting tools.

Sn is the chemical symbol for Tin, derived from its Latin name 'Stannum'. Tin is a post-transition metal in group 14 of the periodic table, commonly used in soldering and coating other metals to prevent corrosion.

K is the chemical symbol for Potassium, derived from its Latin name 'Kalium'. Potassium is an alkali metal in group 1 of the periodic table, essential for nerve function and maintaining fluid balance in living organisms.

Zn is the standard chemical symbol for zinc, derived from its German name 'Zink'. Zirconium uses Zr, helium is He, and hydrazine sulfate is a compound, not an element with a single symbol.

Copper is a metal with excellent electrical conductivity. Nitrogen, Sulphur, and Selenium are all non-metals found on the right side of the periodic table.

Carbon (C) is a non-metal found in group 14. Barium (Ba), Copper (Cu), and Cobalt (Co) are all metals, with Barium being an alkali earth metal and Copper/Cobalt being transition metals.

Sulfur (S) is a non-metal in group 16. It is not a metal, and while some sources may call it a metalloid, standard classification places it firmly as a non-metal based on its properties.

Tungsten is used as the filament in electric bulbs due to its extremely high melting point (3,422°C) and ability to withstand high temperatures without melting. Iron and copper have much lower melting points and would quickly melt at the temperatures required for incandescent lighting.

Germanium (Ge) exhibits properties of both metals and non-metals, placing it in the metalloid category. It has electrical conductivity between that of metals and insulators, making it useful in semiconductors. The correct answer is C because Ge is classified as a metalloid in the periodic table, not a pure metal or non-metal.

Ink is a complex mixture containing dyes, pigments, solvents, and other additives that do not chemically bond in fixed ratios. It cannot be classified as an element (single type of atom) or a compound (fixed chemical formula), and it is certainly not an alloy (metal mixture). The correct answer is A because ink has variable composition.

Au is the chemical symbol for gold, derived from the Latin word 'aurum'. Chemical symbols are standardized internationally, and each element has a unique one- or two-letter symbol.

Ag is the chemical symbol for silver, derived from the Latin word 'argentum'. Gold is Au, Mercury is Hg, and Silicon is Si.

Copper's chemical symbol is Cu, derived from the Latin word 'cuprum'. This symbol is used universally in chemical formulas, equations, and periodic tables to represent copper.