Gold is used to make a super thin layer on the visors of astronauts' helmets because of which property in particular?
a. rare
b. malleable
c. good reflector of heat
d. good conductor of electricity

C. good reflector of heat

Explanation:

In space, sunlight transfers heat by radiation to objects and bodies and this includes satellites and astronauts. In addition, although the peak of the sun's emission is in the visible region of the electromagnetic spectrum, a part is also emitted in infrared (transferring thermal energy or heat) and ultraviolet (especially in the upper part of the Earth's atmosphere).

That is why in space missions, objects and many satellites are covered by thin layers or sheets that reflect this thermal energy and thus avoid damaging the equipment due to high temperatures.

In this sense, among the reflective materials used are aluminum, silver, copper and gold; the latter being the most used because it does not corrode or oxidize (unlike silver and copper) and is more malleable than aluminum.

On the other hand, astronauts are also vulnerable to the effects of infrared radiation, especially their eyes, since the human eye has no receptors in the infrared spectrum. That is why the astronaut's helmet visor is covered with a thin layer of gold to avoid the dangerous effects of solar radiation.

b) phosphorus pentoxide