Physical_characteristics Gas

drifting smoke particles provide clues movement of surrounding gas.

because gases difficult observe directly, described through use of 4 physical properties or macroscopic characteristics: pressure, volume, number of particles (chemists group them moles) , temperature. these 4 characteristics repeatedly observed scientists such robert boyle, jacques charles, john dalton, joseph gay-lussac , amedeo avogadro variety of gases in various settings. detailed studies led mathematical relationship among these properties expressed ideal gas law (see simplified models section below).

gas particles separated 1 another, , consequently, have weaker intermolecular bonds liquids or solids. these intermolecular forces result electrostatic interactions between gas particles. like-charged areas of different gas particles repel, while oppositely charged regions of different gas particles attract 1 another; gases contain permanently charged ions known plasmas. gaseous compounds polar covalent bonds contain permanent charge imbalances , experience relatively strong intermolecular forces, although molecule while compound s net charge remains neutral. transient, randomly induced charges exist across non-polar covalent bonds of molecules , electrostatic interactions caused them referred van der waals forces. interaction of these intermolecular forces varies within substance determines many of physical properties unique each gas. comparison of boiling points compounds formed ionic , covalent bonds leads conclusion. drifting smoke particles in image provides insight low-pressure gas behavior.

compared other states of matter, gases have low density , viscosity. pressure , temperature influence particles within volume. variation in particle separation , speed referred compressibility. particle separation , size influences optical properties of gases can found in following list of refractive indices. finally, gas particles spread apart or diffuse in order homogeneously distribute throughout container.