Vapor pressure called partial pressure. For example, air at sea level, and saturated with water vapor at 20 °C, has partial pressures of about 2.3 kPa of water, 78 kPa of nitrogen, 21 kPa of oxygen and 0.9 kPa of argon, totaling 102.2 kPa, making the basis for standard atmospheric pressure. Vapor pressure is measured in the standard units of pressure. The International System of Units (SI) recognizes pressure as a derived unit with the dimension of force per area and designates the pascal (Pa) as its standard unit. One pascal is one newton per square meter (N·m or kg·m·s). Experimental measurement
Pascal (programming language) R. Hoare. Pascal programs start with the program keyword with a list of external file descriptors as parameters<ref name="iso/iec 7185:1990 6.10">Pascal ISO 7185:1990 6.10</ref> (not required in Turbo Pascal etc.); then follows the main block bracketed by the begin and end keywords. Semicolons separate statements, and the full stop (i.e., a period) ends the whole program (or "unit"). Letter case is ignored in Pascal source. Here is an example of the source code in use for a very simple "Hello world" program: A type in Pascal, and in several other popular programming languages, defines a variable in such a way