Oxygen, fluorine and iodine are diatomic elements. Flourine is more reactive than the other two because it is the closest away to filling its outer layer of electrons and becoming stable like a noble gas.
The correct answer is the second option. Particulate matter is the air pollutant known to affect people with asthma. It also can cause other illnesses like cough, chest discomfort and a burning sensation in the lungs.
As the temperature of a liquid increases, its viscosity decreases.
election circles the nucleus