Krypton was discovered in 1898 by William Ramsay and Morris Travers. Ramsay named it from Greek 'kryptos' meaning 'hidden'. They found it in residual liquid air after removing oxygen and nitrogen
Graham's law states that gas diffusion rate is inversely proportional to square root of molecular weight. Heavier gases diffuse more slowly than lighter ones. Law applies only to molecular effusion through holes, not diffusion between gases
Viscosity varies significantly with temperature in gases and liquids. Gases show increasing viscosity due to molecular momentum transfer. Liquids exhibit decreasing viscosity due to molecular attraction
Each gas in a mixture has a partial pressure as if occupying its own volume. Total pressure of ideal gas mixture equals sum of partial pressures (Dalton's Law). Partial pressure measures thermodynamic activity of gas molecules. Gases dissolve and react according to partial pressures, not concentrations
Partial pressure is the pressure each gas exerts against its surroundings. Ideal gases interact without attraction and behave like billiard balls. Boyle's Law states pressure increases with volume (k = PV). Charle's Law shows temperature increases with volume (k = V/T)
One mole of ideal gas occupies 22.4 liters at STP. Conversion formula: moles = liters / 22.4. Temperature affects gas volume: higher temperature increases volume. Pressure affects gas volume: higher pressure reduces volume