Why is there an octet rule in writing Lewis structures?

Before we can sketch the Lewis structures of molecules, we must first understand the octet rule. The octet rule asserts that when atoms combine to create compounds, electrons are gained, lost, or shared among them, resulting in a stable electron configuration defined by eight valence electrons as a result. These rules are used in conjunction with the main-group components of the second period.

Explanation:

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c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.