Air Quality and Pollution Overview

A fire blanket works by cutting off the oxygen supply to the flames. Combustion requires oxygen to occur, and by depriving the fire of oxygen, the fire blanket effectively smothers the flames, extinguishing the fire.

Nitrogen is the primary component of air, making up approximately 78% of its volume.

The two main gases in air are nitrogen, which comprises about 78%, and oxygen, which makes up about 21% of the air's volume.

<p>Nitrogen is considered an inert gas because its strong triple bond (N≡N) requires a high activation energy to break. This means that nitrogen is relatively unreactive and participates in few chemical reactions under normal conditions.</p> Signup and view all the answers

<p>Oxygen is essential for combustion, making it a key component in burning fuels and generating energy. Additionally, oxygen is used in medical settings to support patients experiencing breathing difficulties, providing them with the necessary oxygen to oxygenate their blood.</p> Signup and view all the answers

<p>Singapore addresses air pollution by having strict laws on the emission of pollutants and fitting power plants with chemical scrubbers to remove pollutants from waste gases. Additionally, individuals can wear N95 masks to filter out harmful particles during haze episodes.</p> Signup and view all the answers

<p>Combustion is a chemical process involving the rapid oxidation of a substance, producing heat and light. It requires the presence of oxygen, a fuel source, and a source of ignition to initiate the reaction.</p> Signup and view all the answers

<p>Carbon dioxide constitutes approximately 0.04% of the air's volume. It is a significant greenhouse gas contributing to global warming and climate change by trapping heat in the atmosphere.</p> Signup and view all the answers

<p>The ozone layer absorbs most of the Sun's harmful ultraviolet (UV) radiation, which can cause sunburn, skin cancer, premature aging, and cataracts. Without the ozone layer, these harmful UV rays would reach the Earth's surface in higher amounts, putting life at risk.</p> Signup and view all the answers

<p>Chlorofluorocarbons (CFCs) are synthetic chemicals containing chlorine, fluorine, and carbon. They were widely used as refrigerants, propellants in aerosol sprays, and in manufacturing processes. CFCs rise to the stratosphere, where they are broken down by UV radiation releasing chlorine atoms. These chlorine atoms react with ozone molecules, breaking them down and depleting the ozone layer.</p> Signup and view all the answers

<p>In the stratosphere, UV radiation breaks apart CFC molecules, releasing chlorine atoms. These highly reactive chlorine atoms react with ozone (O3) molecules, breaking them down into oxygen molecules (O2) and chlorine monoxide (ClO). The chlorine monoxide can then react with another ozone molecule, releasing chlorine atoms back into the cycle, which can continue depleting ozone.</p> Signup and view all the answers

<p>Ozone at ground level is a major component of smog and is harmful to human health and the environment. It can cause respiratory problems, damage crops, and contribute to acid rain. While ozone in the stratosphere is essential for absorbing harmful UV radiation, ozone at ground level is a by-product of air pollution and is detrimental to life.</p> Signup and view all the answers

<p>Sunglasses with UV filters block harmful ultraviolet (UV) radiation from the sun, protecting our eyes from damage. Excessive exposure to UV rays can cause a range of eye problems, including cataracts (clouding of the lens), macular degeneration (damage to the center of the retina), and pterygium (a growth on the conjunctiva).</p> Signup and view all the answers

<p>Stratospheric ozone is beneficial as it filters out most of the Sun’s harmful UV radiation, protecting life on Earth. Ozone at ground level is harmful and is a major component of smog, contributing to respiratory problems, crop damage, and acid rain. Ozone in the stratosphere is formed naturally through reactions involving oxygen and sunlight, while ground-level ozone is primarily a result of air pollution from human activities.</p> Signup and view all the answers

<p>Clouds have a limited effect on blocking UV radiation. While thick clouds can block some UV radiation, they primarily scatter it, redirecting it in different directions. This means some UV radiation still reaches the Earth’s surface even when clouds are present, making it crucial to protect ourselves with UV filters.</p> Signup and view all the answers

<p>The Montreal Protocol, an international agreement signed in 1987, aimed to phase out the production and consumption of ozone-depleting substances like CFCs. This global effort has significantly reduced the amount of these chemicals in the atmosphere, leading to a gradual recovery of the ozone layer. However, ongoing challenges remain, such as the need to monitor the effectiveness of the agreement and address the use of alternative substances that could potentially harm the ozone layer.</p> Signup and view all the answers

<p>The ozone layer absorbs ultraviolet radiation, reducing the amount that reaches the Earth's surface.</p> Signup and view all the answers

<p>Ozone molecules form when oxygen molecules interact with UV radiation from the sun.</p> Signup and view all the answers

<p>Chlorofluorocarbons (CFCs), found in aerosol propellants and refrigerants, are responsible for ozone depletion.</p> Signup and view all the answers

<p>The Montreal Protocol was signed in 1987, committing to restrict the production and release of CFCs.</p> Signup and view all the answers

<p>Burning fossil fuels increases carbon dioxide levels in the atmosphere, contributing to global warming.</p> Signup and view all the answers

<p>Plants absorb carbon dioxide during photosynthesis, helping to regulate its levels in the atmosphere.</p> Signup and view all the answers

<p>The ozone layer is expected to fully heal around the year 2075.</p> Signup and view all the answers

<p>The ozone hole may have contributed to increased skin cancer rates in affected countries by allowing more UV radiation to reach the surface.</p> Signup and view all the answers

<p>Greenhouse gases trap long wavelength radiation emitted from the Earth's surface, preventing it from escaping into space and thus retaining heat.</p> Signup and view all the answers

<p>Methane has a greenhouse effect that can be up to 80 times stronger than carbon dioxide.</p> Signup and view all the answers

<p>The carbon cycle helps balance the intake and output of carbon dioxide, maintaining stable levels in the atmosphere.</p> Signup and view all the answers

<p>Excessive greenhouse gases can lead to extreme temperatures, making Earth too hot like Venus, which is inhospitable for life.</p> Signup and view all the answers

<p>The combustion of fossil fuels and deforestation are two major contributors to the increase in atmospheric carbon dioxide.</p> Signup and view all the answers

<p>A certain level of greenhouse effect is necessary to trap heat, keeping the Earth's temperature suitable for supporting life.</p> Signup and view all the answers

<p>Clearing forests reduces the number of plants that can absorb carbon dioxide, while also releasing stored carbon into the atmosphere.</p> Signup and view all the answers

<p>Factors such as ocean temperature, wind speed and direction, and humidity influence the climate of an area.</p> Signup and view all the answers

<p>About 70%.</p> Signup and view all the answers

<p>They would be permanently flooded due to a sea level rise of more than 60 m.</p> Signup and view all the answers

<p>It causes coral reefs to bleach and marine habitats to be lost.</p> Signup and view all the answers

<p>Glacier-fed river levels would change, initially rising but eventually drying up.</p> Signup and view all the answers

<p>Property is destroyed and lives may be lost, and coastal farmland's fertility may decrease due to saltwater deposition.</p> Signup and view all the answers

<p>It could disrupt ocean currents that redistribute heat and stabilize global climate patterns.</p> Signup and view all the answers

<p>It would disrupt climate-stabilizing ocean currents and potentially impact global weather patterns.</p> Signup and view all the answers

<p>It dissolves the shells of crustaceans, impacting commercially important fish populations.</p> Signup and view all the answers

<p>Fractional distillation takes advantage of the unique boiling points of different gases in air. Air is first liquefied at extremely low temperatures. As the liquefied air warms up slowly inside the chamber, gases with lower boiling points like nitrogen boil off first and are collected separately. As the temperature continues to rise, argon with a slightly higher boiling point boils off next, allowing for their separate collection.</p> Signup and view all the answers

<p>Combustion of fossil fuels, such as coal and oil, and volcanic eruptions are two major sources of sulfur dioxide pollution.</p> Signup and view all the answers

<p>Air purifiers are popular in Singapore because they help improve indoor air quality by removing harmful particles and pollutants that can negatively impact respiratory health.</p> Signup and view all the answers

<p>Acid rain forms when sulfur dioxide and nitrogen oxides react with oxygen in the air to create acidic compounds. These compounds dissolve in rainwater, forming acidic solutions that can damage vegetation, harm aquatic life, and corrode buildings made of limestone, marble, and metals.</p> Signup and view all the answers

<p>Natural sources of air pollution are those that occur without human intervention, such as volcanic eruptions, wildfires, and lightning. Anthropogenic sources are caused by human activities, including industrial emissions, combustion engine emissions, and man-made fires.</p> Signup and view all the answers

<p>Both NO and NO₂ can cause respiratory problems in humans. They contribute to the formation of acid rain, damage vegetation, and reduce visibility.</p> Signup and view all the answers

<p>Inert atmospheres prevent reactions between the substances being processed and the surrounding air, ensuring product purity and preventing unwanted reactions at high temperatures.</p> Signup and view all the answers

<p>The boiling point of a gas is directly related to its molecular structure and the strength of intermolecular forces between its molecules. Gases with weaker intermolecular forces have lower boiling points and will boil off first during fractional distillation, allowing for their separation from gases with higher boiling points.</p> Signup and view all the answers

Air is approximately 78% nitrogen, 21% oxygen, and 1% other gases.

Nitrogen makes up about 78% of the air and is largely inert.

Oxygen constitutes about 21% of the air and is vital for combustion.

A rapid oxidation reaction that requires oxygen and produces heat and light.

A protective layer in the Earth's stratosphere that absorbs most of the Sun's harmful UV radiation.

Substances in the air that can harm human health and the environment, such as sulfur dioxide and carbon monoxide.

The process in which carbon is exchanged among the atmosphere, land, water, and living organisms.

The long-term heating of Earth's climate due to human activities, primarily fossil fuel burning.

Inert gases like argon used in high-temperature processes.

Process to separate gases based on their boiling points.

The temperature at which nitrogen turns to gas: -196°C.

Natural or human activities that release harmful gases.

Pollutant from fossil fuel combustion causing breathing issues.

Gases from vehicle engines that affect air quality.

Rain containing strong acids due to air pollutants.

A colorless gas produced by incomplete combustion of carbon-based fuels.

A greenhouse gas produced by anaerobic decay and livestock waste.

Pollutants from vehicle combustion that can cause smog and irritation.

A form of oxygen that can irritate the eyes and respiratory system, affecting breathing.

Compounds that deplete the ozone layer, used in refrigeration and aerosol sprays.

Harmful sun rays that cause skin damage and eye problems, blocked by ozone.

A molecule made of three oxygen atoms formed by UV radiation interaction.

Chemical compounds containing chlorine, fluorine, and carbon that harm the ozone layer.

The reduction of the ozone layer due to pollutants like CFCs.

An international treaty to phase out substances that deplete the ozone layer.

Invisible rays from the sun that can cause skin cancer and ozone breakdown.

The process by which plants convert carbon dioxide and water into organic matter.

The trapping of heat in the Earth's atmosphere by greenhouse gases.

Gases in the atmosphere that trap heat, including carbon dioxide and methane.

The most common greenhouse gas, comprising 0.04% of the air by volume.

A period starting in the 18th century marked by increased fossil fuel use and carbon emissions.

The average weather conditions in an area over a long period.

Clearing forests increases carbon dioxide levels and reduces carbon absorption.

Communities rely on melt-water from glaciers for drinking and irrigation.

If ice caps melted completely, sea levels could rise by more than 60 m.

Adding fresh water to the ocean can disrupt ocean currents, affecting global climate.

Melting of glaciers affects river levels and can lead to flooding or drought.

Climate change can lead to loss of fertile land, decreasing global food production.

Climate change increases intensity and frequency of storms like typhoons and tornadoes.

Increased temperatures can cause coral bleaching and loss of marine habitats.

Increased ocean acidity may dissolve the shells of crustaceans, threatening marine life.