Before the Decoupling

question 48

Multiple Choice

Before the decoupling:

• A)the Universe was transparent to radiation.
• B)the Universe was opaque to radiation.
• C)protons and electrons combined to form atoms.
• D)there was more helium than hydrogen.
• E)deuterium produced electrons and positrons.

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Definitions:

Paleontologists

Scientists who study the history of life on Earth through the examination of fossilized remains and traces of organisms.

Carbon Dating

A method used to determine the age of an object containing organic material by measuring the decay rate of carbon-14 isotopes.

Rock Layers

Strata or beds of sedimentary rock that have been deposited over time, providing clues to Earth's geological history.

Hominins

Members of the human lineage, including modern humans and all our direct ancestors, characterized by bipedalism and larger brain sizes than other primates.