MCQ Detailed View

Metals are widely used in daily life, but their toxicity levels can vary significantly. Some metals, like copper and silver, are essential in small amounts for biological functions but can become toxic at higher concentrations. Other metals, such as lead or mercury, are highly toxic even in trace amounts.

Among the options given — silver, iron, copper, and gold — gold is considered non-toxic and biologically inert. This means it does not react easily with other substances in the body and is safe for long-term contact. Gold has been historically used in jewelry, dental work, and even in medicine due to its chemical stability and lack of toxicity.

Silver has mild antibacterial properties and is used in medical applications, but prolonged exposure can cause a condition called argyria, which turns the skin bluish-gray. Copper is essential for enzymes in the human body, but excess copper can lead to liver or kidney damage. Iron is necessary for blood production, but high doses can result in iron poisoning.

Gold’s chemical inertness makes it unique among metals. It does not corrode, oxidize, or react with most chemicals under normal conditions, which ensures its safety for humans. In nanotechnology and medical applications, gold nanoparticles are widely studied because they are biocompatible and non-toxic.

Understanding the toxicity of metals is an important part of inorganic chemistry and materials science. It helps in selecting metals for medical, industrial, and daily use, ensuring safety while maintaining functional properties.

In summary, the correct answer is Gold, as it is non-toxic, chemically stable, and safe for human use. This knowledge is essential for students studying chemistry, metallurgy, or applications of metals in health and industry.