Why Did the Era of Nuclei End When the Universe

question 1

Multiple Choice

Why did the era of nuclei end when the universe was about 380,000 years old?

• A)All the free particles had combined to form the nuclei of atoms.
• B)The universe had expanded and cooled to a temperature of about 3,000 K,cool enough for stable,neutral atoms to form.
• C)Neutrinos and electrons were finally able to escape the plasma of the early universe and no longer heated the other particles.
• D)Photons were finally able to escape the plasma of the early universe and no longer heated the hydrogen and helium ions.
• E)No theory can explain this.

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Definitions:

Orthopneic Position

A sitting position to relieve respiratory difficulty in which the client leans over and is supported by an overbed table across the lap.

Chronic Obstructive Pulmonary Disease

A group of progressive lung diseases, including emphysema and chronic bronchitis, that restrict airflow and cause breathing difficulties.

Dyspnea

Difficult or laboured breathing.

Osteoporosis

Demineralization of the bone.