Life Appeared on Earth

question 2

Multiple Choice

Life appeared on Earth

• A) as one-celled organisms and remained so over most of Earth's history.
• B) very early in Earth's history.
• C) after most of Earth's history was already over.
• D) the day before yesterday.
• E) within the last 1 million years.

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Definitions:

C-C π Bond

A C-C π bond is a type of covalent bond formed from the sideways overlap of p-orbitals, allowing for electron sharing between carbon atoms in double or triple bonds.

Carbon-Carbon Bonds

The covalent bond between two carbon atoms in a molecule, forming the backbone of organic compounds.

π Bond

A type of covalent bond between atoms that results from the sideways overlap of p orbitals, allowing for electron sharing.

Rings

Cyclic molecules in chemistry that consist of a series of connected atoms forming a closed loop.