The hemoglobin test is often used to check for anemia, usually along with a hematocrit or as part of a complete blood count (CBC) . The test may be used to screen for, diagnose, or monitor a number of conditions and diseases that affect red blood cells (RBCs) and/or the amount of hemoglobin in blood.he hemoglobin test is often used to check for anemia, usually along with a hematocrit or as part of a complete blood count (CBC) . The test may be used to screen for, diagnose, or monitor a number of conditions and diseases that affect red blood cells (RBCs) and/or the amount of hemoglobin in blood.
Volcanoes form at hot spots in the Earth's crust, at convergent plate boundaries where subduction of oceanic crust is occurring, and at divergent plate boundaries where gaps i â¦ n the crust are being infilled with rising magma.
Volcanoes form when magma reaches the Earth's surface, causing eruptions of lava and ash. They occur at destructive (compressional) and constructive (tensional) plate boundaries. The immediate effects of volcanic eruptions can be devastating, but they may be beneficial in the long term. Key facts A volcano is formed by eruptions of lava and ash. Volcanoes are usually cone shaped mountains or hills. When magma [magma: Magma is molten rock.] reaches the Earth's surface it is called lava. When the lava cools, it forms rock.