The law of multiple proportions is..
Different compounds made of same element have different proportions by mass of those elements.
"-2" is the electric charge of the oxygen ion among the following choices given in the question. It actually needs two electrons to complete the stable outer shell. The correct option among all the options that are given in the question is the third option or option "C". I hope that the answer has helped you.
<h3><u>Answer</u>;</h3>
A. When a reaction is at chemical equilibrium, a change in the system will cause the system to shift in the direction that will balance the change and help the reaction regain chemical equilibrium.
<h3><u>Explanation</u>;</h3>
- Le Chatelier's principle states that when a change or a "stress" is placed on a system that is at equilibrium, the system will shift in such a way to relieve that change or stress.
- The stresses include; changing the concentration of reactants or products, altering the temperature in the system and changing the pressure of the system.
- Therefore; <u><em>when a chemical reaction is at equilibrium and experiences a change in pressure, temperature, or concentration of products or reactants, the equilibrium shifts in the opposite direction to offset the change. </em></u>
Answer : The chemical symbol for the element that results from this process is, (Ar) for argon.
Explanation :
Electron capture : In this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. Simply, a proton and an electron combines together to form a neutron. Mass number does not change in this process.

The equation for the given reaction is,

Thus, the chemical symbol for the element that results from this process is, argon (Ar).
<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>