As a radioactive element emits gamma radiation only, the atomic number of the element increases or decreases

It actually remains the same.

Explanation: Gamma radiation does not affect the atomic number or the atomic mass.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

b. is the answer hoped i