When metals are required in a ultra pure state, the zone refining method is used. The principle-employed states that the impurities, which lower the melting point of a metal remain preferentially dissolved in the liquid phase and purer metal will emerge in the solid phase.

Correct Option: B

When metals are required in a ultra pure state, the zone refining method is used. The principle-employed states that the impurities, which lower the melting point of a metal remain preferentially dissolved in the liquid phase and purer metal will emerge in the solid phase.

n 1905, it was Einstein who suggested the concept of light having a dual nature; particle and wave nature. In a similar way, Louise de Broglie suggested that electron also exhibits a dual nature. Broglie derived a mathematical expression to prove the wave nature of electron along with particle nature. He gave the following relation:- ë =h/mí, where ë is the wavelength of electron, m is mass of an electron and í is the frequency.

Correct Option: A

n 1905, it was Einstein who suggested the concept of light having a dual nature; particle and wave nature. In a similar way, Louise de Broglie suggested that electron also exhibits a dual nature. Broglie derived a mathematical expression to prove the wave nature of electron along with particle nature. He gave the following relation:- ë =h/mí, where ë is the wavelength of electron, m is mass of an electron and í is the frequency.

Photochemical smog is a unique type of air pollution which is caused by reactions between sunlight and pollutants like hydrocarbons and nitrogen dioxide (NO and NO₂). Other components of the photochemical smog include Ozone (O₃) formaldehyde, peroxy benzoyl nitrate (PBzN), peroxy acetyl nitrate (PAN) and acrolein. The formation of photochemical smog can be expressed in the simple terms as: Hydrocarbons + NO_x + sunlight

Correct Option: D

Photochemical smog is a unique type of air pollution which is caused by reactions between sunlight and pollutants like hydrocarbons and nitrogen dioxide (NO and NO₂). Other components of the photochemical smog include Ozone (O₃) formaldehyde, peroxy benzoyl nitrate (PBzN), peroxy acetyl nitrate (PAN) and acrolein. The formation of photochemical smog can be expressed in the simple terms as: Hydrocarbons + NO_x + sunlight

Arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and selenium are some of the metals called ‘heavy’ because of their high relative atomic mass. They persist in nature and can cause damage or death in animals, humans, and plants even at very low concentrations.

Correct Option: B

Arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and selenium are some of the metals called ‘heavy’ because of their high relative atomic mass. They persist in nature and can cause damage or death in animals, humans, and plants even at very low concentrations.

Bauxite, an aluminium ore, is the world’s main source of aluminium. Bauxite is primarily comprised of aluminum oxide compounds (alumina), silica, iron oxides and titanium dioxide. It is refined through the Bayer chemical process into alumina. Alumina is refined into pure aluminum metal through the Hall– Héroult electrolytic process.

Correct Option: B

Bauxite, an aluminium ore, is the world’s main source of aluminium. Bauxite is primarily comprised of aluminum oxide compounds (alumina), silica, iron oxides and titanium dioxide. It is refined through the Bayer chemical process into alumina. Alumina is refined into pure aluminum metal through the Hall– Héroult electrolytic process.