Humus

question 60

Multiple Choice

Humus:

• A) is the material always comprising the topmost soil horizon.
• B) is dark, organic-rich material formed by bacterial decay.
• C) is leaf-litter.
• D) must include sediments.
• E) none of the above

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Definitions:

Entropy Term

A thermodynamic quantity representing the degree of disorder or randomness in a system, significant in predicting the spontaneity of processes.

ΔG°

Standard Gibbs free energy change, a thermodynamic quantity indicating the spontaneity of a reaction at standard conditions; negative values suggest spontaneity.

Exothermic

A chemical reaction or process that releases heat to its surroundings.

Endothermic

Describes a process or reaction that absorbs energy from its surroundings, typically in the form of heat.