Air Pollution And Ozone

Explanation
Ozone is good high up in the atmosphere because it forms a protective layer called the ozone layer. This layer absorbs most of the sun's harmful ultraviolet (UV) radiation, preventing it from reaching the Earth's surface. UV radiation can cause various health issues in humans and other living organisms, such as skin cancer, cataracts, and damage to the immune system. Therefore, having ozone high up in the atmosphere is beneficial as it helps to shield us from the harmful effects of UV radiation.

Explanation
Smog is the most common name for ground-level ozone pollution. Smog is a type of air pollution that occurs when pollutants like nitrogen oxides and volatile organic compounds react with sunlight to form ozone near the Earth's surface. It is characterized by a hazy appearance and can have harmful effects on human health and the environment.

Explanation
Ozone is formed when oxygen molecules (O2) are broken down by ultraviolet (UV) radiation from the sun, resulting in two oxygen atoms (O). These oxygen atoms can then react with other oxygen molecules to form ozone (O3). However, the presence of certain pollutants is necessary for this reaction to occur. Oxides of nitrogen (NOx), which are produced from the burning of fossil fuels, and hydrocarbons, which are released from sources such as vehicle emissions and industrial processes, are the two pollutants that need to be present in order to form ozone.

Explanation
Smog is caused by the release of pollutants into the atmosphere, which react with sunlight to form a mixture of harmful gases and particles. Cars, factories, and fumes from paint are all sources of these pollutants. Vehicles emit exhaust gases, factories release industrial emissions, and paint fumes contain volatile organic compounds that contribute to smog formation. Therefore, all of the mentioned options - cars, factories, and fumes from paint - can cause smog.

Explanation
Most smog forms during the summer. This is because the combination of sunlight, high temperatures, and pollutants from sources such as vehicle emissions and industrial processes leads to the formation of ground-level ozone, which is a major component of smog. The warm weather and stagnant air during the summer months allow these pollutants to accumulate and react, resulting in the formation of smog.

Explanation
Most smog forms during sunny and hot weather because sunlight and heat react with pollutants, such as nitrogen oxides and volatile organic compounds, resulting in the formation of ground-level ozone and other harmful pollutants. These reactions are facilitated by the presence of sunlight and high temperatures, which increase the rate of chemical reactions and the dispersion of pollutants in the air. Rain and wind can help to disperse and remove pollutants, while snow and hail are less conducive to smog formation. Therefore, the correct answer is sunny and hot.

Explanation
Motor vehicles are the biggest source of smog because they emit pollutants such as nitrogen oxides, volatile organic compounds, and particulate matter. These pollutants react with sunlight to form ground-level ozone, a major component of smog. The exhaust from cars, trucks, and buses releases large amounts of these pollutants into the atmosphere, contributing significantly to smog formation in urban areas.