Suppose you need to heat food. What wave type from the electromagnetic spectrum could you use?

Microwave radiation

Explanation:

This radiation is the one used in microwaves.

Infrared

Explanation:

Infrared light is used by electrical heaters, cookers for cooking food, and by infrared cameras which detect people in the dark. Infrared light has frequencies which are absorbed by some chemical bonds. The internal energy of the bonds increases when they absorb infrared light, which causes heating.

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.

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.