The vacuum of outer space has essentially zero air. Because sound is just vibrating air, space has no air to vibrate and therefore no sound. If you are sitting in a space ship and another space ship explodes, you would hear nothing. So, in order for sound to travel, there has to be something with molecules for it to travel through. On Earth, sound travels to your ears by vibrating air molecules. In deep space, the large empty areas between stars and planets, there are no molecules to vibrate. There is no sound there.
Crushing pressure. Human bodies are used to air pressure. The air pressure in our lungs, ears and stomachs is the same as the air pressure outside of our bodies, which ensures that we don't get crushed. Our bodies are also flexible enough to cope when the internal and external pressures aren't exactly the same.
A single photon carries an energy equal to

where h is the Planck's constant and f is the frequency of the photon.
This means that the higher the frequency of the light, the higher the energy. Among the 5 different options mentioned by the problem, the light with highest frequency is ultraviolet, which has frequencies in the range [3-30] PHz, while visible light (red, blue, green) and infrared have lower frequency, so ultraviolet light has the highest energy per photon.
Answer:
Explanation:
11 = y/3+7
collecting like terms
11 - 7 = y/3
4 = y/3
multiplying both sides by 3 gives us
12 = y
therefore
y = 12