Carbon dioxide concentration is typically between what percentages?

The correct answer indicates that carbon dioxide concentration typically ranges between 6% and 9%. This range reflects conditions found in various environments, particularly those influenced by human activity or specific industrial processes, where CO2 levels can rise due to combustion and other chemical processes.

In natural conditions, the concentration of CO2 in the atmosphere is much lower, around 0.04% or 400 parts per million, but in enclosed spaces or specific applications, concentrations can increase significantly. Understanding the typical ranges is crucial for ensuring proper ventilation and air quality in workplaces and other settings where elevated CO2 levels may occur.

The other options suggest ranges that are either too low or too high for typical scenarios. For example, concentrations below 4% are generally safe and commonly found in outdoor air, while concentrations above 10% can be hazardous and are usually only encountered in controlled or confined environments under specific circumstances. Thus, the range of 6% to 9% accurately represents conditions where increased CO2 can become a factor to monitor for safety and health considerations.