The Duration of the Oxygen-Fusing Stage in the Core of a Massive

question 173

Multiple Choice

The duration of the oxygen-fusing stage in the core of a massive star is considerably shorter than the duration of the carbon-fusing stage. One main reason for this is that

• A) carbon is a solid, while oxygen is a gas.
• B) oxygen fusion does not begin until the contracting core has reached a higher temperature than the temperature at which carbon fusion is possible.
• C) the electron degeneracy inhibits the carbon reaction, but it has been removed by the time oxygen fusion begins.
• D) there are more fusion shells surrounding the oxygen fusion core than there are around the carbon fusion core. The shells prevent the escape of oxygen before it can fuse.

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Definitions:

Relative Efficiency

A measure of how effectively an entity (such as a firm or economy) utilizes its resources compared to another, often used to identify opportunities for improvement.

Absolute Efficiency

A state where resources are allocated in the most effective way possible, achieving maximum output with given inputs.

Natural Endowment

Resources found in nature that have economic value or utility, such as minerals, forests, and water.

Merchandise Trade Deficit

A situation where a country's imports of goods exceed its exports of goods, leading to a negative balance of trade.