Microfossil Evidence Suggests That Life

question 15

Multiple Choice

Microfossil evidence suggests that life

• A) originated when the Earth formed 4.6 billion years ago
• B) originated about 3.0 billion years ago
• C) existed 3.85 billion years ago
• D) existed before about 3.0 billion years ago and may well have existed before 3.5 billion years ago

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Definitions:

Allyl Cation

A positively charged species (ion), specifically a reactive intermediate with the structure CH2=CH-CH2+.

LUMO

The Lowest Unoccupied Molecular Orbital, which is the lowest energy orbital that can accept electrons.

Pentadienyl Cation

A positively charged ion with a structure derived from pentadiene, typically involved in organic reactions.

LUMO

The Lowest Unoccupied Molecular Orbital, representing the lowest-energy orbital that can accept an electron.