A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels consist of a solid three-dimensional network that spans the volume of a liquid medium and ensnares it through surface tension effects. Shaving creams in a can are commonly dispensed as a foam or a gel.

Correct Option: C

A gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels consist of a solid three-dimensional network that spans the volume of a liquid medium and ensnares it through surface tension effects. Shaving creams in a can are commonly dispensed as a foam or a gel.

Magnetite is a mineral, one of the two common naturally occurring oxides of Iron. It is the most magnetic of all the naturally occurring minerals on Earth.

Correct Option: B

Magnetite is a mineral, one of the two common naturally occurring oxides of Iron. It is the most magnetic of all the naturally occurring minerals on Earth.

Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulfide.

Correct Option: D

Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulfide.

Nitrogen fertilizers are often made using the HaberBosch process which uses natural gas (CH4+) for the hydrogen and nitrogen gas from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia as the end product. This ammonia is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea.

Correct Option: A

Nitrogen fertilizers are often made using the HaberBosch process which uses natural gas (CH4+) for the hydrogen and nitrogen gas from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia as the end product. This ammonia is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea.

An antiknock agent is a gasoline additive used to reduce engine knocking and increase the fuel's octane rating by raising the temperature and pressure at which ignition occurs. Tetraethyllead was admixed with gasoline (petrol) beginning in the 1920s as an inexpensive octane booster which allowed engine compression to be raised substantially, which in turn increased vehicle performance and fuel economy.

Correct Option: B

An antiknock agent is a gasoline additive used to reduce engine knocking and increase the fuel's octane rating by raising the temperature and pressure at which ignition occurs. Tetraethyllead was admixed with gasoline (petrol) beginning in the 1920s as an inexpensive octane booster which allowed engine compression to be raised substantially, which in turn increased vehicle performance and fuel economy.