What is the properties of gas particles?

Answer 1

The characteristics or properties of gases vary widely. Some gases are transparent, some have a strong smell, some dissolve in water, and some react violently with almost any substance. Other gases exhibit exactly the opposite properties. The chemical structure of gases also varies greatly.

A number of gases have a characteristic color. For example, fluorine gas appears green, chlorine appears yellow-green, and nitrogen dioxide (a component of smog) appears red-brown. The majority of gases, however, are colorless. Many gases, including nitrogen, oxygen, and hydrogen, are odorless. Ammonia, however, has a sharp, pungent odor. Because fuel gases such as methane, propane, and butane are odorless, an intensely odorous sulfur compound is added to them to ensure early detection should these gases leak from their containers. Some gases, such as carbon dioxide, dissolve well in water. Many others, including nitrogen, hydrogen, and oxygen, are only slightly soluble in water. The solubility of any gas decreases as the temperature of the gas increases, and it increases as the pressure increases.

Some gases can react with other substances to form new chemical compounds. Oxygen, for example, reacts with iron to form rust. The chemical reactivity of gases varies widely. Oxygen, chlorine, and fluorine are extremely reactive gases. In fact, fluorine will react with almost any other substance; even water and glass will burn in a fluorine atmosphere. At the other extreme are the noble gases, which are generally considered inert (unreactive). Neon, a noble gas, is not known to react with any other substance.

Gas particles are the smallest units into which a gas can be divided without changing the chemical properties of the gas. These particles can either be single atoms or molecules (combinations of atoms). The noble gases, such as neon and helium, are composed of individual atoms. Other gases, including carbon dioxide (CO2), methane (CH4), and ammonia (NH3), contain atoms of more than one element chemically bound together in molecules. Some gases that contain only a single element, such as hydrogen, oxygen, and nitrogen, are also composed of molecules. The oxygen in Earth's atmosphere, for example, consists mostly of oxygen molecules (O2) rather than individual oxygen atoms (O).