1. ___Mg +
O2 → __Mgo
What type of reaction is shown

Explanation:

In first one it should be 2Mg

and in second = 2Mgo

hope it helps

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: