The difference between living things and nonliving things is little things that we call is senses like sight, taste, touch, smell, and hearing. For example a human or animal can react to someone or something touching them. For a nonliving thing such as a rock can't react to someone touching them unless u force them to.
<h2>Answer: Radio waves </h2><h2 />
Radio waves are a type of electromagnetic radiation with wavelengths between 10 m to 10,000 m. In the electromagnetic spectrum this wavelength is longer than infrared light and therefore, it goes beyond the visible spectrum.
This type of electromagnetic waves is very well reflected in the ionosphere, the layer of the atmosphere through which they travel directly or using repeaters.
In addition, they are very useful to transport information, being important in telecommunications. They are used not only for conventional radio transmissions but also in mobile telephony and TV.
It should be noted that since radio signals have large wavelengths, they can be diffracted around certain obstacles, such as hills and mountain ranges, preventing the signal from reaching its destination.
Therefore, the correct option is C.
The point with the greatest potential energy is B.
The potential energy of an object is depends on the relative distance between the object and the ground and its mass. The higher the object is from the ground the greater the potential energy posses.
Potential energy (P.E) = mgh
Where m is the mass, g is the gravity and h is the height from the ground to where the object is.
Since the mass and gravity is constant in this case, only the height will determine the point with the greatest P.E and that point is B.
Answer;
C.It is the minimum amount of material needed to sustain a fission reaction.
Explanation;
-A critical mass is the smallest or the minimum amount of fissile material needed for a sustained nuclear chain reaction. A critical mass must be achieved in order for the chain reaction to continue and release the atomic energy. A critical mass is needed for both a nuclear reactor and an atomic or hydrogen bomb.
-The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings.
