Gases from "summary" of Student's Guide to Fundamentals of Chemistry by Jo A. Beran
Gases are composed of molecules that are in constant motion and have no definite shape or volume. They can be compressed and become more dense, or expand and become less dense, depending on the temperature and pressure of their environment. Gases also interact with other substances to form new compounds.- Gases are formed of molecules that are so widely separated they can move freely among each other in all directions. These molecules have minimal attraction to each other, making it easier for them to move around and diffuse.
- The most common example of a gas is air which consists of many elements including oxygen, nitrogen and carbon dioxide. Depending on its composition, various changes in physical properties can be observed.
- A gas can take the shape and fill the entire space of its container as long as sufficient pressure is supplied. Moreover, when the external pressure increases, the gas particles will require lesser space to fit into.
- Gases such as methane, ethane, ammonia and hydrogen sulfide act as valuable sources of chemical reactions as their gaseous state facilitates better mixing of reactants and products.
- Not only are gases essential components of the atmosphere but also play an important role in natural events such as dust devils, hurricanes and thunderstorms. In addition, they are also released during volcanic eruptions where heat and pressure cause certain materials to become unstable and then converted into gases.
- When it comes to temperature control, the thermal energy of a gas is inversely proportional to its pressure. An increase in pressure leads to a decrease in temperature while an increase in temperature results in a drop in pressure.
