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How can you describe the life during Precambrian era? Most of the life that existed during the Precambrian Time span were prokaryotic single-celled organisms. These earliest forms of life resembled cyanobacteria. They were photosynthetic blue-green algae that thrived in the extremely hot, carbon dioxide-rich atmosphere. What process change the Earth’s environment during the Precambrian time? […]
What happens when a tsunami approaches the shore? Despite these losses, tsunamis still reach the coast with tremendous amounts of energy. Depending on whether the first part of the tsunami to reach the shore is a crest or a trough, it may appear as a rapidly rising or falling tide. Local bathymetry may also cause […]
What theory states that continents drift or move? Alfred Wegener proposed that the continents were once united into a single supercontinent named Pangaea, meaning all earth in ancient Greek. He suggested that Pangaea broke up long ago and that the continents then moved to their current positions. He called his hypothesis continental drift. What hypothesis […]
What two areas did the Bering land bridge connect? The Bering Land Bridge connected North America and Asia. What two continents are connected by the Bering Strait? Artist’s rendering of concept for the Bering Strait bridge. The Bering Strait was last crossed by humans 20,000 years ago during the ice age, when ice formed a […]
How are metal ions held together? Metallic bonding is often described as an array of positive ions in a sea of electrons. The metal is held together by the strong forces of attraction between the delocalised electrons and the positive ions. What force hold the metal together? metallic bonds What electrostatic force holds metallic bonds […]
How is each layer of the atmosphere heated? The troposphere is the lowest layer of the Earth’s atmosphere. Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does. The heat is spread through the troposphere because the air is slightly […]
What is the average climate in Colombia? Much of Colombia lies in the warm altitudinal zone below 1000 meters, with mean annual temperatures above 23.9°C (75°F). The average annual temperatures are between 16.7°C (62.1°F) to 23.9°C (75°F) at altitudes ranging from 1000 meters to 2000 meters. Is Colombia hot or cold? Colombia is a generally […]
How and why does temperature vary with height in the atmosphere? The troposphere is heated from the ground, so temperature decreases with altitude. Because warm air rises and cool air sinks, the troposphere is unstable. In the stratosphere, temperature increases with altitude. The stratosphere contains the ozone layer, which protects the planet from the Sun’s […]
What elements of contrast are employed in the story an episode of war? Contrast is a key element in this excellent short story, and Crane especially uses ironic contrast to highlight the absurdity and meaninglessness of war and yet how it has such a profound impact on individuals. What happens to cause the lieutenant’s injury […]
Does vinegar affect bones? Eating a well balanced diet that includes foods rich in calcium is an important way to keep bones healthy. In this activity, vinegar, an acid, will slowly dissolve the calcium in the bones, making the bones weak. Does vinegar soften bones? Vinegar is a mild acid. Soaking the bone in vinegar […]