How Have Scientists Used Isotopic Analysis to Determine That the Rise

question 26

Multiple Choice

How have scientists used isotopic analysis to determine that the rise of atmospheric CO2 is mostly from the burning of fossil fuels?

• A)Since 14C is an unstable isotope,scientists have dated the atmospheric carbon to the period since the Industrial Revolution.
• B)Both coal and oil contain a high proportion of 14C.By analyzing,14C /12C ratios,scientists have been able to determine the source based on this fact.
• C)The low proportions of 13C and 14C within atmospheric CO2 indicates the source is fossil carbon.
• D)14C concentrations are much higher in urban areas than in rural areas,indicating fossil fuels must have a higher 14C /12C ratio than carbon from other sources.

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Definitions:

Inconclusive

Not leading to a firm conclusion or definitive result; leaving questions unanswered.

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A breathing technique that involves breathing in through the nose and out through tightly pressed (pursed) lips to improve breath control.

Emphysema

A long-term, progressive disease of the lungs that primarily causes shortness of breath due to over-inflation of the air sacs (alveoli).

Pneumothorax

The presence of air or gas in the pleural space that causes collapse of the lung.