Object distances are always negative according to the Cartesian sign convention
An element is composed of millions of atoms and a compound is composed of molecules. When an atom reacts with another atom, a molecule is formed.
For example, if sodium reacts with chloride, it forms sodium chloride (Common salt). Here, sodium and chloride are elements and sodium chloride is a molecule. In this way, millions of atoms of sodium reacts with chloride and forms common salt.
Again, when the common salt is mixed with other compounds such as water, it forms a mixture.
I'm not sure what the alien Theory says or if there really is such a theory. If the theory says that aliens definitely exist and that they have visited Earth in the past then the theory is totally and completely without any kind of support. It's not scientific in any way because there is no evidence for such a claim. It may be thought to be probable but no solid evidence has ever been presented.
Answer:
14 N
Explanation:
The tension in the second string is puling both the masses of 20 kg and 8 kg with acceleration of 0.5 m s⁻²
So tension in the second string = total mass x acceleration
= 28 x .5 = 14 N . Ans..
Answer:
<em>C. It is made from three layers of semiconductors.</em>
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Explanation:
<em>Bipolar transistors (pnp and npn) are usually made from a sandwich of three semiconductors layers</em>. The main charge carriers are holes and electrons. An npn transistor has two semiconductor junctions that share a thin middle positively enhanced region (the material is enhanced with impurities rich in holes which are the positive charge carriers), and a pnp transistor has two semiconductor junctions that share a thin middle negatively enhanced region (material is enhanced with impurities rich in electrons, the negative charge carriers).
