Which phenomena help form Earth’s magnetic field? Check all that apply. weather on Earth’s surface
rotation of Earth on its axis
metal liquifying in the inner core
revolutions of Earth around the Sun
rock solidifying in the outer mantle
motion of metal in Earth’s outer core

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.

nuclear fission produces elements that are heavier than helium.

the elements that are used in nuclear fission and their products are much heavier than helium.