Answer:
option A
Explanation:
The correct answer is option A
The binary star system is the system in which two stars are continuously orbiting each other,
In the eclipsing binary system, two stars revolve about there center of mass and in this system one one-star eclipse another star.
Spectroscopic binary stars are found from the observation of radial velocity and the brighter member of such binary can be seen to have continuously changed the wavelength and periodic velocity.
When the pairs of stars appear to change position in the sky then it is known as visual binary.
Nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus.
Nuclear fusion of light elements releases the energy that causes stars to shine and hydrogen bombs to explode.
Nuclear fusion of heavy elements (absorbing energy) occurs in the extremely high-energy conditions of supernova explosions.
Nuclear fusion in stars and supernovae is the primary process by which new natural elements are created.
It is this reaction that is harnessed in fusion power.
It takes considerable energy to force nuclei to fuse, even those of the lightest element, hydrogen.
You clearly identified the pole you're talking about as the
"north-seeking" pole. Assuming your integrity and sincerity,
we would then naturally expect that pole to seek north, and
point to Earth's north magnetic pole.
I'm confident in this answer also because I have several of
these devices hanging from the ceiling of my office, and I can
attest to the fact that on most clear days, they do in fact point
toward Earth's north magnetic pole.
Answer:
This is because below 4°c, water unlike other materials becomes less dense when it's temperature is further lowered.
Explanation:
Due to the unusual nature of water; at about 4°c, the behavior of the density of water in relation to its temperature reverses. This means that water becomes less dense as it becomes colder below 4°c. The colder parts therefore floats to the top of the water body while the warmer part sinks allowing the top to freeze and the remaining body below to remain in its liquid state.
The freezing of the top of the lake alone protects the remaining depth of water from freezing by acting as an insulator and preventing further heat loss from the water to the ambient space. If this had not been the case, and water froze all through, marine lives will freeze to death and it will be more difficult to melt the ice come the next summer.
This behavior is due to the hydrogen bonding of the water molecules.
