9. When using the half-life of C-14, if an artifact had 4.0 g of C-14 originally, and it now has 1.0 g of C-14, what is the approximate age of the artifact?
(half life of C-14 is 5730yrs)

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:

plasma - state of matter made up of electrically charged particles