Page 7 - part 2ffinal_Version_Science_BB_Prim.4_(2nd_term)_2024-2025[1]_Neat
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Mechanical Weathering Chemical Weathering
Breaking without changing the rock’s Breaking with changing the rock’s
nature nature, new substance is formed
Wind mechanical weathering. Oxygen + iron in some rocks =
Wind pushes the sand, friction red rust weakens and break the rocks.
between sand & rocks then rocks are
broken.
Water mechanical weathering. Water dissolves minerals then
Water runs over rocks; it dissolves dissolved minerals combine again
substances then rocks are broken forming new limestone caves.
down.
Plant roots mechanical weathering. Acid rain falls on rocks and dissolves
Roots grow inside the cracks, they minerals causing breaking of rocks.
become wider then rocks are broken.
Temperature mechanical Tiny plant-like organisms “Lichens”
weathering produce acids dissolve minerals
causing breaking down of rocks.
With repeated freeze/
melt cycles, rock
breaks into pieces.
Second Term 33
