Chemistry and Materials Science

Consider the following statements: Statement I: Some rare earth elements are used in the manufacture of flat television screens and computer monitors. Statement II: Some rare earth elements have phosphorescent properties. Which one of the following is correct in respect of the above statements?

In which of the following are hydrogels used ? 1. Controlled drug delivery in patients 2. Mobile air-conditioning systems 3. Preparation of industrial lubricants Select the correct answer using the code given below:

Consider the following: 1. Aerosols 2. Foam agents 3. Fire retardants 4. Lubricants In the making of how many of the above are hydrofluorocarbons used?

Consider the following statements: 1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts. 2. Carbon fibres once used cannot be recycled. Which of the statements given above is/are correct?

With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements: 1. Its fibres can be blended with wool and cotton fibres to reinforce their properties. 2. Containers made of it can be used to store any alcoholic beverage. 3. Bottles made of it can be recycled into other products. 4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions. Which of the statements given above are correct?

Consider the following statements: 1. Other than those made by humans, nanoparticles do not exist in nature. 2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics. 3. Nanoparticles of some commercial products which enter the environment are unsafe for humans. Which of the statements given above is/are correct?

Water can dissolve more substances than any other liquid because

Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?

With reference to carbon nanotubes, consider the following statements: 1. They can be used as carriers of drugs and antigens in the human body. 2. They can be made into artificial blood capillaries for an injured part of human body. 3. They can be used in biochemical sensors. 4. Carbon nanotubes are biodegradable. Which of the statements given above are correct?

“3D printing” has applications in which of the following? 1. Preparation of confectionery items 2. Manufacture of bionic ears 3. Automotive industry 4. Reconstructive surgeries 5. Data processing technologies Select the correct answer using the code given below:

With reference to the use of nano-technology in health sector, which of the following statements is/are correct? 1. Targeted drug delivery is made possible by nanotechnology. 2. Nanotechnology can largely contribute to gene therapy. Select the correct answer using the code given below.

Which of the following is/are the example/examples of chemical change? 1. Crystallization of sodium chloride 2. Melting of ice 3. Souring of milk Select the correct answer using the code given below.

There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why? 1. They can accumulate in the environment, and contaminate water and soil. 2. They can enter the food chains. 3. They can trigger the production of free radicals. Select the correct answer using the code given below.

Graphene is frequently in news recently. What is its importance? 1. It is a two-dimensional material and has good electrical conductivity. 2. It is one of the thinnest but strongest materials tested so far. 3. It is entirely made of silicon and has high optical transparency. 4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs. Which of the statements given above are correct?

Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why? 1. China, which is the largest producer of these elements, has imposed some restrictions on their export. 2. Other than China, Australia, Canada and Chile, these elements are not found in any country. 3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements. Which of the statements given above is/are correct?