Endogenic and exogenic forces

Rainfall and steep slopes can increase erosion and mass movement. In exams consider slope and water important factors.

Glaciers erode rocks by abrasion on the surface. In exams consider glacial action an exogenic process.

Subsidence may be linked with internal movement of the Earth's crust. In exams treat both uplift and subsidence as endogenic.

Temperature change can break rocks without chemical change. In exams treat it as physical weathering.

In chemical weathering water and gases can alter minerals. For exams remember clues such as solution and oxidation.

In an earthquake internal energy is released suddenly causing vibrations. In exams consider it an immediate endogenic event.

The correct answer is B. Exogenic forces operate at or near Earth’s surface and are powered by external agents or surface conditions, such as rainwater, rivers, wind, glaciers, and changes of temperature. Chemical weathering by rainwater alters minerals in a rock and gradually weakens or breaks it down, so it is exogenic. A is wrong because continental collision is driven by internal tectonic energy. C is also internal because mantle convection is caused by Earth’s internal heat. D is wrong because faulting and tectonic mountain building result from forces inside Earth. A useful warning is that a process may be visible at the surface but still be endogenic if its energy comes from within Earth.

Wind transports sand and deposits it at suitable places. For exams treat sand dunes as wind deposition.

The direct answer is A, Weathering. Weathering means the breaking down or chemical alteration of rock at or very near its original place. No necessary movement of the material is involved. Step by step: first, rock is weakened by heat, water, air, plants, or animals; second, it cracks, breaks, or changes chemically; third, the fragments may remain there. Erosion is different because it includes removal by running water, wind, ice, or waves. Option A is correct because it describes in-place breakdown. Option B is wrong because erosion involves wearing away and carrying material. Option C is wrong because transportation means movement itself. Option D is wrong because deposition means material is laid down after being transported. Memory cue: weathering breaks, erosion removes, transportation carries, and deposition settles.

In erosion rock or soil material is removed and carried away. For exams remember both removal and transport.

Endogenic forces can create relief through uplift and subsidence. In exams treat basic relief formation as endogenic.

The direct answer is A, landslide. Gravity attracts mass downward, so its role is especially clear when soil and rock move down a slope. In a landslide, material becomes unstable, gravity overcomes resistance, and the mass moves downslope. Option A is correct because a landslide is a type of mass movement directly controlled by gravity. Option B, folding, mainly results from compressional tectonic forces that bend rock layers; gravity is not the clearest defining force. Option C, volcanic eruption, is driven mainly by pressure and rising magma and gases, although gravity can affect the falling material. Option D, crustal uplift, is an endogenic tectonic movement caused mainly by forces inside Earth. Exam cue: downhill movement of a large mass usually points to gravity and mass wasting.

Water wind glaciers and waves erode or deposit surface material. In exams treat them as exogenic agents.

Endogenic processes are linked with crustal movement and internal energy. In exams look at both source and effect.

In mass movement loose material moves downward due to gravity. In exams use slope and gravity as key clues.

Earthquakes and volcanic activity can cause major changes in a short time. In exams link sudden change with endogenic events.

Weathering erosion and mass movement slowly wear down mountains. In exams treat lowering of height as exogenic action.

Weathering and erosion are linked with breaking and removing rocks at the surface. In exams treat folding and faulting as endogenic.

Folding and faulting are linked with internal movements of the crust. In exams place them under diastrophic processes.

Uplift is endogenic and river erosion is exogenic. In combined action questions identify both stages.

Endogenic and exogenic processes are distinguished by source and place of action. In exams first check the energy source.

Isostasy is related to crustal balance and uplift-subsidence. In exams connect it with internal crustal balance.

Broken material moves downslope due to gravity so it is mass movement. In exams take slope and gravity as key clues.

Climate and slope can change the speed of weathering erosion and mass movement. In exams consider climate important in external processes.

Tension can make rocks break and slip forming faults. In exams connect tension and breaking with faulting.