The ionic charge of an element in group 6a is 2–. -true -false

True. These ions are of a 2- charge. Oxygen is an example. It will form a 2- charge if ionize.  

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.

explanation:

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )