Answer :
A compound is formed as a result of a chemical reaction.
A compound is formed due to the chemical reaction between certain chemical elements and particles in specific conditions. In short, a compound is a chemical substance which is the combination of one or more chemical elements. Examples of compounds are [tex]C0_2[/tex] , [tex]H_20[/tex],etc. That is why it is termed as the result of a chemical reaction. So the option a is correct.
When we go through the other options, isotopes are not formed as a result of any chemical reaction as they are chemical elements in its natural form.
Now particles beta and particles alpha are the byproducts of nuclear reactions and not the chemical reactions.
Learn more about the compound at https://brainly.com/question/26487468
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