FOCUS Clarity, structure, definitions, explanation.

INTRODUCTION A volcanic eruption may seem sudden, but it is usually the result of pressure building over time. This text explains why volcanoes erupt and why clear structure matters in scientific explanation.

DEFINITION Magma is melted rock beneath the Earth's surface. When magma reaches the surface, it is called lava.

INTRODUCTION A volcanic eruption may seem sudden, but it is usually the result of pressure building over time.

CAUSE OF ERUPTION Volcanoes erupt because pressure builds below the ground. Deep inside the Earth, heat can melt rock and form magma. This magma contains gases. As pressure grows, the magma looks for a path upward. If the pressure becomes too strong, an eruption can happen.

WHAT HAPPENS DURING AN ERUPTION When an eruption begins, lava, ash, gas, and rock fragments may burst from the opening. Some eruptions are gentle and slow. Others are violent and dangerous. The type of eruption depends on the kind of magma, the amount of gas, and how easily pressure can escape.

WHY EXPLANATION NEEDS ORDER An explanatory text should begin with the main cause before describing the result. If a writer describes lava and ash first but explains pressure later, the reader may understand what happened but not why it happened. Clear structure helps the explanation make sense.

CONCLUSION Volcanoes erupt because heat, magma, gas, and pressure interact beneath the ground. A good explanatory text makes these relationships clear by defining key terms, organising ideas carefully, and showing cause before effect.

AFTER YOU READ Why is the difference between magma and lava important in this explanation?