<em><u>Protons</u></em><em><u> = Positive Charge</u></em>
<em><u>Neutrons</u></em><em><u> = Neutral Charge/No Charge</u></em>
<em><u>Electrons</u></em><em><u> = Negative Charge</u></em>
<em>This one's simple: electrons have a negative charge, protons have a positive charge and neutrons — as the name implies — are neutral.</em>
<u><em>Protons</em></u>
<em>Elements are differentiated from each other by the number of protons within their nucleus. For example, carbon atoms have six protons in their nucleus. Atoms with seven protons are nitrogen atoms. The number of protons for each element is known as the atomic number and does not change in chemical reactions. In other words, the elements at the beginning of a reaction -- known as the reactants -- are the same elements at the end of a reaction -- known as the products.</em>
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<em><u>Neutrons</u></em>
<em>Although elements have a specific number of protons, atoms of the same element may have different numbers of neutrons and are termed isotopes. For example, hydrogen has three isotopes, each with a single proton. Protium is an isotope of hydrogen with zero neutrons, deuterium has one neutron, and tritium has two neutrons. Although the number of neutrons may differ between isotopes, the isotopes all behave in a chemically similar manner.</em>
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<u><em>Electrons</em></u>
<em>Electrons are not bound as tightly to the atom as protons and neutrons. This allows electrons to be lost, gained or even shared between atoms. Atoms that lose an electron become ions with a +1 charge, since there is now one more proton than electrons. Atoms that gain an electron have one more electron than protons and become a -1 ion. Chemical bonds that hold atoms together to form compounds result from these changes in the number and arrangement of electrons.</em>
Answer:
During the pumping of hot air into the expansion valve.
Answer : The number of moles of oxygen needed are, 1.5 moles.
Explanation :
The balanced chemical reaction will be:
Now we have to calculate the moles of oxygen.
From the balanced chemical reaction we conclude that,
As, 6 moles of water vapor produces from 5 moles of oxygen
So, 1.80 moles of water vapor produces from 
moles of oxygen
Therefore, the number of moles of oxygen needed are, 1.5 moles.
