How can temperature lead to weathering of rocks?
A. Rocks move faster when they are heated, which can cause the pieces to eventually move away.
B. Rocks expand and contract when they are heated and cooled which cause them to break.
C. Rocks become ice when they get cold, which can later melt and wash away.
D. Rocks can melt when they become hot, which can lead to pieces breaking off.
B. Rocks expand and contract when they are heated and cooled which cause them to break.
B. Rocks expand and contract when they are heated and cooled which cause them to break.
The correct answer is B. Rocks expand and contract when they are heated and cooled, leading to weathering. When rocks are exposed to changes in temperature, such as intense heat during the day and cool temperatures at night, they undergo a process called thermal expansion and contraction.
Here's how temperature leads to the weathering of rocks:
1. Heating: When rocks are exposed to high temperatures, they expand due to thermal expansion. The heat causes the minerals in the rocks to expand unevenly because different minerals have different coefficients of thermal expansion. This can create stress within the rock, leading to the development of fractures and cracks.
2. Cooling: Conversely, when the temperature drops, rocks contract due to thermal contraction. The contraction causes the rock to contract unevenly, further widening existing cracks or creating new ones.
3. Repeated cycles: These cycles of heating and cooling, which commonly occur in many regions due to daily and seasonal temperature changes, can weaken the structure of the rocks over time. As the cracks and fractures gradually widen, they provide more pathways for water, air, and other weathering agents to penetrate into the rock.
4. Weathering agents: Once the cracks and fractures are opened up, weathering agents such as water, wind, and ice can enter and exert further pressure on the rock. Water can freeze and expand in the cracks, exerting considerable force and widening them further. Wind-carried particles may also abrade the rock surfaces, contributing to the breakdown of the rocks.
Ultimately, the repeated expansion and contraction, combined with the action of weathering agents, can lead to the breakdown and disintegration of rocks over time.