### One Atomosphere

pressure caused by the weight of the atmosphere. at sea level, it has a mean value of one atmosphere but reduces with increasing latitude

### S.T.P.

a unit of pressure; the pressure that will support a column of mercury 760 mm high at sea level

### Absolute Zero

the theoretical temperature at which substances possesses no thermal energy to -273.15°C or -459.67°F

### The Kelvin Temperature Scale

an international temperature scale whih agrees with the Kelvin absolute temperature scale within the limits of eperimental determination

### Direct Proportion

the relation between quanties whoes ratio remains constant, when A changes, then also B changes by the same factor.

### Inverse Proportion

the relationship between two quantities trough factors that are multiplicative inverse

### Combined Gas Law

the law that describes the relationship among the pressure temperature and the volume of an enclosed gas

### Boyle's Law

the principle that a constant temperature of the volume of a confined ideal gas varies inversely with its pressure

### Charle's Law

the principle that the volume of a given mass of ideal gas is proportional to its temperature as long as its pressure remains constant

### Dalton's Law of Partial Pressures

the principle that the pressure exerted by a mixture of gasses in a fixed volume is equal to the sum of the pressures that each gas would exert of it scoupled the whole volume

### Grahm's Law

the princiole that the rates of diffusion and effusion of a gas are inversely proportional to the square root of its density

### Avgatro's Law

two equal volumes of gas at the same temperature and pressure, contain the same number of molecules