The unit for expressing the carbon dioxide concentration in the atmosphere is ppm. It refers to

Question

BlackTom AI · Accepted Answer

The question asks: The unit for expressing the carbon dioxide concentration in the atmosphere is ppm. It refers to

- The provided answer option is: d. molecules per million in a certain volume

To analyze, we first clarify what ppm represents in atmospheric science. Ppm stands for parts per million and is used to express extremely dilute concentrations. In the context of gases, ppm is commonly understood as a ratio of the number of CO2 molecules to the total number of molecules in a given volume of air, effectively a count of molecules per million molecules. This aligns with the intuitive idea of measuring how many CO2 molecules exist per one million molecules of the atmosphere sample, which is a volume-based way to express a molar or volumetric fraction in gases that mix uniformly.

Now, why this interpretation makes sense: in a gas mixture, the composition by volume (or by mole) is proportional to the number of particles present. Expressing concentration as ppm therefore conveys the proportion of CO2 molecules among all atmospheric molecules, scaled to one million molecules. This framing is widely used because it remains meaningful across varying total pressures and temperatures, as long as the mixture is الغازية (gas-like) and well-mixed.

Assuming there were other options, we would evaluate them similarly:
- If an option claimed ppm is a simple percentage, that would be inaccurate because ppm is not a percent unless explicitly converted (1% = 10,000 ppm).
- If an option suggested ppm measures mass per mass (ppm by mass), that would be incorrect in atmospheric chemistry where ppm typically denotes a mole or volume fraction, not a mass ratio.
- If an option asserted ppm refers to time units or energy units, that would be a clear misrepresentation of what ppm measures in this context.

In summary, the statement described in the provided option corresponds to the conventional meaning of ppm in atmospheric science: a ratio expressed as molecules per million in a given volume of air, reflecting the proportion of CO2 among all atmospheric molecules.

Dashboard QUIZ Multiple choice questions - Part 1

The unit for expressing the carbon dioxide concentration in the atmosphere is ppm. It refers to

View Explanation

Log in for full answers

Similar Questions

In a consumer society, many adults channel creativity into buying things

Economic stress and unpredictable times have resulted in a booming industry for self-help products

People born without creativity never can develop it

A product has a selling price of $20, a contribution margin ratio of 40% and fixed cost of $120,000. To make a profit of $30,000. The number of units that must be sold is: Type the number without $ and a comma. Eg: 20000

Which of the following statement regarding cost is correct:

Under the assumptions used in cost-volume-profit analysis, as the activity increases:

The CVP and break-even analysis are supported by a range of important assumptions. Which of the following is not an assumption of the CVP:

The break-even point is that at which:

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler