Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Weathering is the process where rocks are broken down into smaller pieces called sediment. This can be physical (mechanical) or chemical. An example of chemical weathering is when oxygen reacts with iron in rocks to form rust, represented as .
Erosion is the movement of weathered particles from one place to another by agents such as water, wind, ice, and gravity.
Deposition occurs when the agents of erosion drop their load of sediment in a new location, creating new landforms like deltas or sand dunes.
Ice Wedging is a form of physical weathering. When water () seeps into cracks in rocks and freezes, its volume increases by approximately , exerting pressure that cracks the rock further.
Slow Changes to Earth's surface include weathering and erosion which take millions of years, while Rapid Changes include events like landslides, volcanic eruptions, and earthquakes.
The pH of rainwater can cause chemical weathering. Normal rain has a , but acid rain with a lower can dissolve minerals like limestone ().
📐Formulae
💡Examples
Problem 1:
During a cold winter, water fills a crack in a granite rock. If the volume of the liquid water is , what happens to the rock when the temperature drops below ?
Solution:
The water will freeze and expand to approximately .
Explanation:
Because the volume of ice is greater than the volume of liquid water (), the expanding ice exerts outward pressure on the walls of the crack, causing the rock to split. This is known as physical weathering.
Problem 2:
A river flows into the ocean and slows down. Over many years, a large triangular landform called a delta forms. Which process is primarily responsible for this?
Solution:
Deposition
Explanation:
As the velocity of the water decreases, the river can no longer carry the heavy sediment. The sediment settles at the mouth of the river, building up new land over time.
Problem 3:
Identify the type of weathering: A statue made of limestone () begins to lose its facial features after years of exposure to acid rain.
Solution:
Chemical Weathering
Explanation:
The acidic components in the rain react chemically with the calcium carbonate () in the stone, dissolving the mineral and changing the chemical composition of the surface.