Carbon dioxide is one of the components of air, with a concentration of about 0.033%. It is directly present in the intake and excretion of animal and plant life. If there is only oxygen in the air without carbon dioxide, then people's breathing will not be so coordinated, balanced and comfortable. Therefore, when rescuing patients with hypoxia in high mountains, on the one hand, the patient should be given oxygen, and on the other hand, a certain amount of carbon dioxide should also be given to the patient.
Plants need carbon dioxide for photosynthesis. Applying carbon dioxide as fertilizer in greenhouses can increase crop yields.
Carbon dioxide cannot support combustion and is denser than air. It can be poured from one container into another like a liquid. If carbon dioxide is allowed to cover a burning object, it can cause the object to follow. The air is cut off and combustion ceases. Therefore, some fire extinguishers use carbon dioxide produced by chemical reactions to extinguish fires.
Solid "dry ice" of carbon dioxide can be used to make artificial rainfall, create clouds and mist in film photography, etc. The principle is because dry ice absorbs a large amount of heat when it evaporates, causing the water vapor in the surrounding air to condense into small water droplets.
In recent years, due to the massive increase in the use of fossil fuels, approximately 17 billion tons of carbon dioxide are emitted into the atmosphere every year. Coupled with the destruction of forest plants, the concentration of carbon dioxide in the atmosphere has increased, becoming an atmospheric pollutant. .
Some data show that when the concentration of carbon dioxide in the air reaches 1%, people will breathe faster; when the concentration reaches 2%, they will feel uncomfortable; when the concentration reaches 10%, it can cause suffocation and death.
Carbon dioxide and other gases can absorb long-wave radiation heat from the ground, increasing the atmospheric temperature and causing climate warming. This effect is called the greenhouse effect. According to scientists' predictions, if the current growth of carbon dioxide is calculated, by 2030 AD, if the earth's temperature is 4.5°C higher than it is now, the ice in Antarctica may melt, causing sea levels to rise, which will eventually lead to global flooding and a large number of people. Fertile farmland and cities will be flooded, while fertile farmland at high altitudes will turn into large deserts due to high temperatures, with disastrous consequences. So scientists are researching ways to prevent it. The theme of World Environment Day in 1989 was "Beware of Global Warming".
Protecting the environment and preventing pollution are of far-reaching significance to human survival.
On August 13, 1894, British chemist Ramsey and physicist Rayleigh reported at a meeting that they had discovered an element with strange properties.
This element exists in a gas state and is indifferent to any of the most active and powerful substances. Therefore, it is named "argon", which means "lazy". After the "lazy" gas argon was discovered in the air, scientists successively separated four gases: helium, neon, krypton, and xenon from the air. After research, they found that helium, neon, argon, krypton, and xenon are structurally identical. They have similar characteristics and are "inert" in nature, so they are named "inert gases". After carefully studying the periodic law of elements, Ramsey added a new group to the periodic table of elements - group zero. This family is the noble gas family. With the development of science and technology, people have obtained many "inert gas" compounds through experiments. People have realized that the "inertness" of inert gases is only relative, because their reserves in nature are very small, so they renamed inert gases. Is a rare gas. Rare gases can emit different colored lights when energized. The flashing neon lights on billboards in shops and squares are the result of rare gases.