Mass is not expressed in kilometers (km). That is a measure of distance. Mass is expressed in units of kilograms (kg)
6.829*103 km
1 Km = 1000m 1m = 1000mm so 110mm expressed in m = 110 divided by 1000 = 0.11m 0.11m expressed as Km = 0.11 divided by 1000 = 0.00011Km
Mercury: diameter 4880 km mass 3.302e+23 kg Venus: diameter 12104 km mass 4.856e+24 kg Earth: diameter 12756 km mass 5.9742e+24 kg Mars: diameter 6796 km mass 6.419e+23 kg Jupiter: diameter 142984 km mass 1.899e+27 kg Saturn: diameter 120536 km mass 5.685e+26 kg Uranus: diameter 51118 km mass 8.683e+25 kg Neptune: diameter 49528 km mass 1.0243e+26 kg
Km - kilometers, is a unit for distance, and can't be used to measure mass.
Atomic mass
Average weight of an element expressed in Atomic Mass units.
Mass is.
Mass
The molar mass is expressed in grams.
Gram Atomic Mass
Mercury: diameter 4880 km mass 3.302e+23 kg Venus: diameter 12104 km mass 4.856e+24 kg Earth: diameter 12756 km mass 5.9742e+24 kg Mars: diameter 6796 km mass 6.419e+23 kg Jupiter: diameter 142984 km mass 1.899e+27 kg Saturn: diameter 120536 km mass 5.685e+26 kg Uranus: diameter 51118 km mass 8.683e+25 kg Neptune: diameter 49528 km mass 1.0243e+26 kg
land mass: 329,560 square km water mass: 4,200 square km