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rhodium

Primary Information
Secondary Information

Definition

Rhodium is a chemical element with the symbol Rh and atomic number 45. It is a silvery-white, hard, and chemically inert transition metal. Rhodium is the rarest of the platinum group metals.

Rhodium has a melting point of 1963°C and a boiling point of 3695°C. It is very resistant to corrosion and does not tarnish easily. Rhodium is also a very good conductor of heat and electricity.

Rhodium is found in very small amounts in the Earth's crust. It is extracted from the ores of platinum and nickel.

Rhodium is used in a variety of applications, including:

  • Jewellery: Rhodium is used to plate jewellery to make it more resistant to tarnishing. Rhodium plating is often used on white gold jewellery to give it a bright, white finish.
  • Catalytic converters: Rhodium is used in catalytic converters to help reduce emissions from cars. Catalytic converters use rhodium to convert harmful pollutants into less harmful gases.
  • Electronics: Rhodium is used in electronics to make contacts and connectors that are resistant to corrosion. Rhodium contacts are often used in high-end electronics, such as cell phones and computers.
  • Medical devices: Rhodium is used in medical devices to make them more resistant to infection. Rhodium is often used in pacemakers and other implanted medical devices.

How can the word be used?

Rhodium is a rare element, and it is not found in large quantities in nature.

rhodium

Different forms of the word

Noun:

  • a chemical element with the symbol Rh and atomic number 45. It is a silvery-white, hard, and brittle metal.

Adjective:

  • of or relating to rhodium.

Etymology

The word "rhodium" comes from the Greek word "rhodon", which means "rose".

The first recorded use of the word "rhodium" in English was in 1804.

The word "rhodium" is named after the rose-coloured salts of the element. It was discovered by William Hyde Wollaston in 1803 in platinum ore from South America.

Question

What is Rhodium used for?

AQA Science Exam Question and Answer

Question:

Explain the role of rhodium in catalytic converters and its significance in reducing vehicle emissions. Provide an overview of how rhodium functions within catalytic converters and its impact on air quality.

Answer:

Rhodium plays a pivotal role in catalytic converters, which are essential components in automotive exhaust systems designed to reduce harmful emissions from vehicles. Catalytic converters contain a combination of precious metals, including rhodium, to facilitate chemical reactions that convert harmful pollutants into less harmful substances.

Rhodium is specifically involved in catalyzing the reduction of nitrogen oxides (NOx), a group of pollutants that contribute to smog and respiratory problems. During the catalytic conversion process, rhodium acts as a catalyst, promoting the reaction between nitrogen oxides and carbon monoxide to form nitrogen and carbon dioxide, both of which are less harmful to the environment and human health.

This role of rhodium in catalytic converters has a significant impact on air quality, particularly in urban areas with high vehicle density. By facilitating the conversion of harmful emissions into less harmful compounds, rhodium contributes to the reduction of pollutants that can contribute to air pollution and associated health issues.