The three main geochemical cycles of earth are and these geochemical cycles continuously remove and add material on earth.

a) water, fire, and earth
b) hydrologic, heat, and rock
c) hydrologic, rock, and tectonic

The correct option is C.

The geochemical cycle refers to the pathway through which certain chemical elements pass on the surface of the earth and underneath the surface of the earth. The cycle is described as geochemical because it involved both the geological and chemical factors. The three major geochemical cycles that exist on the earth are hydrologic, rock and tectonic cycles. The hydrologic cycle deal with the movement of water round the earth surface, both underneath and on the surface of the earth, the rock cycle deal with rocks while the tectonic cycle deal with rock deformation process.

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally