Answer:
PET polymer or Polyethylene terephthalate is also known as Terylene. In the PET polymer, the ester linkage between the monomers is formed by the reaction of the OH group of ethylene diol (glycol) and the CO2H group of terephthalic acid.
In the family of polyester, PET is considered as the mostly used thermoplastic polymer resin.
It is used widely in clothing fibers, as liquid and food containers, and as a substance for engineering resins. In the United Kingdom it is known as terelyne, in the United States as Dacron, and in Russia as Lavsan.
Your answer to #2 is <span>There are several differences between a </span>physical<span> and chemical </span>change in matter<span> or substances. A </span>physical change<span> in a substance doesn't </span>change<span> what the substance is. In a chemical </span>change<span> where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. </span>
In the nucleus there are two main subatomic particles: The protons and the neutrons. The number of protons in the nucleus determines the element the atom is: 1 proton = hydrogen , 99 protons = Einsteinium , 6 protons = carbon etc.
The number of neutrons in the nucleus varies from atom to atom, even atoms of the same element. This causes the mass of the nucleus to vary slightly and can effect properties such as stability or type of nuclear decay. Atoms of the same element with different masses are called isotopes. They differ by the number of neutrons with the proton in te nucleus:
1 proton + 0 neutrons = 1 particle in the nucleus = hydrogen
1 proton + 1 neutron = 2 particles in the nucleus = deuterium
1 proton + 2 neutrons = 3 particles in the nucleus = tritium
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Answer:
B)
Explanation:
The gravitational force exerted by Earth on objects is directed downward towards Earth's center.
Explanation:
The purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors
or
Most electrical wire is covered in a rubber or plastic coating called insulation. The purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors
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