<span>Matter of all types have gravity, which causes it to attract to each other. The most efficient way for all this matter to congregate is the sphere. As they consolidate, they form the shape. As they compress, temperatures in the center of the mass start to go up and if it hits the proper point, it can ignite and become a star.</span>
By tightening a string you are actually putting more stress on the string you are giving it a new frequency that isn't natural.
Hope this helps
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Calcium has 2 valence electrons
The correct answer to the question is : 1) Converting energy and 2) Within about twenty years, natural gas forms.
EXPLANATION:
In coal fired power plants, the water is heated by burning coals. The heat produced in this process will convert water into steam. The steam is allowed to rotate the turbine. The turbine is attached to a generator which converts the kinetic energy of the steam into electric energy due to electromagnetic induction.
Hence, turbine helps in converting energy.
As per the second question, Walt listed the steps that occur during the formation of natural gas.
The natural gas is produced due to natural phenomenon. For this, millions of years are passed. So, it is a long range process in which the fossil of animals and planets buried beneath the surface are converted into natural gas under high pressure.
Hence, the mistake of Walt is that the natural gas is produced withing twenty years.
