Give a geographical reason for each of the following:

1. Volcanic activity and earthquakes occur in the same belt.
2. All rivers do not form a delta.
3. Chemical weathering is more common in the tropical regions.

1. The volcanoes and earthquakes are associated with each other. Both occur along the faults between the tectonic plates. Therefore, belt of their occurrence is same.
2. When a river flows through a rocky area, and carries very little load because of the steep terrain, it forms a narrow opening at its mouth which gradually widens out into the sea. Such rivers do not form delta.
3. Chemical weathering is more common in the tropical regions because the climate of tropical region is hot and humid. High temperature and presence of moisture increases the rate of reaction thereby increasing the rate of chemical weathering.