The energy absorbed or released when a neutral atom gains one electron

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:

1.solid

2.carbon dioxide

3.helium

it would be d. henry moseley

hope this !

and sorry if i'm late. have a good rest of your day! : d