The Child Advocacy Center is a safe, child friendly location for children to come speak with trained interviewers or one of our medical providers. We know this can be an anxious time for you and your family. When we are able, one of our child advocates will be calling you before the interview or medical evaluation to answer any of your questions.
The thickest parts are under the continents and the thinnest parts are under the oceans. Crust. Earth's crust is made up of several elements: oxygen, 47 percent; silicon, 27 percent; aluminum, 8 percent; iron, 5 percent; calcium, 4 percent; magnesium, potassium and sodium, 2 percent. The crust is divided into huge plates that float on the mantle, the next layer.
Living organisms are composed primarily of carbon, oxygen, and hydrogen. Other elements in living matter include calcium, nitrogen, phosphorus, potassium, and trace amounts of other elements. Water is made up of hydrogen and oxygen. The oceans also contain salt, made up of sodium and chlorine. The atmosphere is mostly made up of the element nitrogen, existing in diatomic form (N2). It also includes oxygen, carbon (in carbon dioxide) and a small amount of other elements.