One could say that the atmosphere is the least dense, but of the surface the crust is the least dense.
The exosphere is the least dense part of the earth's atmosphere.
inner core
It is found in the earth
hot, less dense air rises
Earth is more dense.
The Inner Core is the most dense part of the Earth. It is a solid core of iron and nickel.
The most dense layer of the Earth is the inner core, located at the center of the Earth. It is composed primarily of solid iron and nickel, making it the densest part of our planet.
Both are rocky. Both are dense, but Earth is far more dense than the moon is.
The lithosphere is the solid outer section of Earth, which includes Earth's crust, and the underlying cool, dense, and rigid upper part of the mantle.
The Earth's crust is the thinnest part of Earth's interior, ranging from about 5-70 kilometers (3-44 miles) in thickness. It is divided into two types: continental crust, thicker and less dense, and oceanic crust, thinner and more dense.
The earth's crust is less denser than the mantle.
It is neither. The densest layer is the inner core. The least dense layer is the crust.