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| Q. |
Which of the following statements is correct? |
| A. | Lava and magma both have gas |
| B. | Neither the lava nor the magma has gas |
| C. | Magma has gas while lava has no gas |
| D. | Lava has gas while magma has no gas |
| Answer» A. Lava and magma both have gas | |
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Explanation: Highly viscous lava tends to entrap gas, which form vesicles (bubbles) within the rock as they rise to the surface. Lava with low viscosity tends to easily release bubbling gases as they are formed. Lavas also may contain many other components, sometimes including solid crystals of various minerals, fragments of exotic rocks known as xenoliths and fragments of previously solidified lava. Volcanic eruptions are caused by magma (a mixture of liquid rock, crystals, and dissolved gas) expelled onto the Earth's surface. |
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