Sodium (Na) in Blood. Guide. A sodium test checks how much sodium is in the blood. Sodium is both an electrolyte and mineral. It helps keep the water (the amount of fluid inside and outside the body's cells) and electrolyte balance of the body. Sodium is also important in how nerves and muscles work.hy It Is Done. A blood test to check sodium levels is done to: 1  Check the water and electrolyte balance of the body. 2  Find the cause of symptoms from low or high levels of sodium.
Many of the lakes on the Canadian Shield, including those of the Great Lakes, were created by glacial erosion. Glacial Deposition A large part of the surface of a glacier is covered with a coating of sediment and rock debris.
Glacial Erosion [edit]. The two main ways that glaciers erode the underlying rock are abrasion and plucking. As the thick layer of ice pushes against the underlying rock, it scrapes and polishes the rock surface. As glaciers flow, they scratch the underlying bedrock with all the rocky material they are carrying.