Meteorology is best defined as the study of

Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. Meteorological phenomena are observable weather events which illuminate and are explained by the science of meteorology. Those events are bound by the variables that exist in Earth's atmosphere.

The chief factors comprised by the science of meteorology are temperature, barometric pressure, humidity, sunlight and the interactions of each variable, as well as their variability. An example of meteorology would be the NOAA, who study the ocean and the atmosphere.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

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the answer is na (sodium)