What Quantum Transition Occurs Inside a Cool Hydrogen Atom to Produce

question 45

Multiple Choice

What quantum transition occurs inside a cool hydrogen atom to produce a 21-cm radio photon?

• A) The electron combines with the proton in the nucleus to become a neutron,producing energy.
• B) An electron reverses the direction of its motion in orbit around the proton.
• C) An electron in the ground atomic state reverses its direction of spin with respect to that of the proton.
• D) An electron falls from the level n = 100 to the level n = 99 in the atom.

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Definitions:

Aquifer

An underground layer of water-bearing permeable rock, rock fractures, or unconsolidated materials (gravel, sand, silt) from which groundwater can be extracted.

Karst Topography

A landscape formed from the dissolution of soluble rocks such as limestone, characterized by sinkholes, caves, and underground streams.

Limestone Pillars

Natural columns made of limestone, often formed in karst landscapes through the process of dissolution.

Sinkholes

Depressions or holes in the ground caused by the collapse of a surface layer, often resulting from the dissolution of limestone beneath.