What is the surface of the earth classified as?
Solid shell of the Earth, composed of rock and soil. The thickness varies from 70 - 150 km. Oxygen and Silicon are the two most common elements.
Consists of all the water (oceans, lakes, rivers, groundwater) of the Earth. Average depth of the ocean is 3 - 4 km and cover about 70 percent of the surface.
A shell of gasses that surrounds the Earth and is stratified. Lowest layer (called the Troposphere) is the most important because it contains most of the water vapor and where most of the weather takes place. The layers are divided by changes in temperature. The boundary between layers is called a pause. For example the boundary between the Troposphere and the Stratosphere is called the Tropopause.
Here are a few things to remember.
Two charts in your Reference Tables will help you answer questions about the different parts of the Earth. The Average Chemical Composition chart on page 11 and the Selected Properties of Earth's Atmosphere chart on page 15.