What determines the length of each period in the periodic table?
Week of 9/11 Approximate composition of air (homogeneous mixture): 21% oxygen, 78% nitrogen, 1% other gases o The feeling of needing to breathe when holding breath or suffocating is a result of too much CO2, not a lack of oxygen Pollutants: ozone, carbon monoxide, nitrogen dioxide o Ozone in the stratosphere (ozone layer) is good, protection from UV radiation o Ozone near us (in the troposphere) is not good Carbon monoxide is from burning fossil fuels Nitrogen dioxide is from cars and power plants Major air pollutants: particulate matter, sulfur dioxide, lead, toxic air pollutants Measurement of air pollutants: Pure substance A + Pure substance B = A+B Mixture o 2.23mg + 1
