Answer:
Precipitation is the formation of a solid from a solution. It is necessary to centrifuge the precipitate to exert sufficient forces of gravity to bring the solid particles in the solution to come together and settle
Explanation:
When you centrifuge precipitate it enables the nucleation to form.
Centrifuging the precipitate helps in determining whether a certain element is present in a solution or not.
Answer:
m = 2.01[kg]
Explanation:
This problem can be solved using Newton's second law which tells us that the force applied on a body is equal to the product of mass by acceleration.

where:
F = force = 12.5 [N]
m = mass [kg]
a = acceleration = 6.2 [m/s²]
![12.5=m*6.2\\m = 2.01[kg]](https://tex.z-dn.net/?f=12.5%3Dm%2A6.2%5C%5Cm%20%3D%202.01%5Bkg%5D)
When a star uses up all of it's energy and begins to die, it swells up to become a red giant star. This causes its surface gravity to decrease, thereby allowing some of its mass to escape into space.
A binary star is a pair of stars that orbit each other because of their gravitational attraction to each other. When one member of the binary pair uses up all of its energy and begins to die, it loses mass due to the reduction in surface gravity. But instead of escaping into space, this mass is attracted to the companion star because of its gravitational pull. That increases the mass of the companion star. In a process that takes thousands of years, enough matter is transfered that causes the temperature and pressure to increase sufficiently to result in nuclear fusion reactions on the companion star. When these nuclear reactions become extremely violent, the released nuclear energy increases the brightness of this companion star dramatically, thereby creating a nova.
Therefore, it is the dying of one of the stars in a binary system along with a sufficient transfer of star mass to sustain nuclear reactions that results in a nova.
42- C
43- A
44- C
45- A
46- B
47- D