Clean Water Rule coverage would produce a 2:1 ratio of benefits to costs in implementation after the final rule. Implementation of the rule will discern any implications for environmental justice communities, though it is clear that "meaningful involvement from minority, low-income, and indigenous populations, as well as other stakeholders, has been a cornerstone of development of the final rule." Specific details that have been clarified by the rule are outlined below. A tributary, or upstream water, must show physical features of flowing water – a bed, bank, and ordinary high water mark – to warrant protection. The rule provides protection for headwaters that
Octet rule and used it to help formulate his cubical atom model and the "rule of eight", which began to distinguish between valence and valence electrons. In 1919 Irving Langmuir refined these concepts further and renamed them the "cubical octet atom" and "octet theory". The "octet theory" evolved into what is now known as the "octet rule". The quantum theory of the atom explains the eight electrons as a closed shell with an sp electron configuration. A closed-shell configuration is one in which low-lying energy levels are full and higher energy levels are empty. For example, the neon atom ground state has