Electrical charge on atmospheric aerosols In air pollution control and atmospheric chemistry, what charges can aerosols (suspended particles/droplets) possess?

Introduction / Context:
Aerosols (solid or liquid particles suspended in air) play central roles in visibility reduction, health impacts, cloud processes, and pollutant transport. Their electrical charge influences coagulation rates, deposition behavior on surfaces, and how they respond to electrostatic precipitators. Knowing their possible charge states is basic to both air-quality modeling and control equipment design.

Given Data / Assumptions:

• Aerosols exist across wide size ranges from nanometers to tens of micrometers.
• Charging can occur by diffusion charging (ion attachment), field charging, triboelectric processes, or chemical reactions.
• Ambient air contains ions and charged clusters due to cosmic rays, solar UV, and combustion sources.

Concept / Approach:
Any given aerosol population includes particles that are positively charged, negatively charged, or electrically neutral. The distribution depends on ion balance, particle size, age, and local electric fields. Control devices like electrostatic precipitators are designed to charge particles and then use fields to drive collection, explicitly relying on this variability and controllability of charge states.

Step-by-Step Solution:

Verification / Alternative check:
Field measurements of mobility distributions and ion counters routinely report fractions of positive, negative, and neutral particles; charging models predict mixed states that evolve with residence time and fields.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming “neutral” is default; in fact, small particles can carry single charges frequently, and charge distributions are dynamic.

Final Answer:
combination of all (a), (b) & (c).