Removing and replacing keys on Acer Aspire laptop's keyboard may require a small screwdriver for precision. Keyboard keys of Acer laptops designed for easy removal and replacement.
How to Measure Air Pollution for a Science Fair Project. Pollution is one among the major problems of todayâs world and air pollution is one root cause of many environmental issues. You can use a magnifying glass for this purpose as the dust particles are too tiny to be seen with necked eye. 2  Count the number of dust particles carefully stuck to the Vaseline in each square and note them down on a note book. 3  Use the number of dust particles sticked to the squares as a proof of air pollution.
Particle Pollution (PM) Particle pollution, also called particulate matter or PM, is a mixture of solids and liquid droplets floating in the air. Some particles are released directly from a specific source, while others form in complicated chemical reactions in the atmosphere. Particles come in a wide range of sizes. Particles less than or equal to 10 micrometers in diameter are so small that they can get into the lungs, potentially causing serious health problems. Ten micrometers is less than the width of a single human hair. 1  Coarse dust particles (PM10) are 2.5 to 10 micrometers in diameter. 2  Fine particles (PM2.5) are 2.5 micrometers in diameter or smaller, and can only be seen with an electron microscope.