The answer is the last one (it needs a medium through which to travel) it is not true about radiation. A radiation is the emission of energy in the form of waves or particles through space or through a material medium. This includes; electromagnetic radiation, such as a radio wave, microwaves, visible light, x rays, and gamma radiation.
Answer:

Explanation:
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In this case, according to the given data, it is possible to infer that the gas mixture lies on the 15.0 cm-high column of water, so that the total pressure or atmospheric pressure is given by:

Thus, since the atmospheric pressure is 745 mmHg and the vapor pressure of water is 18 mmHg, the pressure of hydrogen turns out to be:

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Answer: Noble gas configuration is the ionisation of valence electrons using the octet rules.
Explanation:
Noble gases are the halogen, iodine etc. they form molecules using anion valence electrons in order build octet structures.