Q.1 define tectonic plates, mountainous rift and earthquake

Defined as below

Explanation:

Plate tectonics are defined as the pieces of Earth's crust floating over the liquid asthenosphere or the movements of sheets/plates of hard rock over the rigid mantle. Varying in thickness moving in the directions to there orientation. They are either oceanic or continental plates

Rift valleys are generally linear or are highlands that separated by actions of geologic agents. It may be formed by a divergent or a convergent plate movement. 0n earth can occur on all height above mean sea levels. Extraterrestrial Rift valleys have also been found on planets in the solar system.  Example is Eastern valley of africa.

Earthquake is a shaking of the earth from the interior due to the vibrations and waves produced due to the movement of geo-material beneath the earth's crust. These waves are measured on a Richter scale and range from 1 to 12 caused by sliding of the earth plates from the convergent, divergent and transform boundaries. Like the ring of fire an earthquake prone region.