Science StarterScience StarterTrue or FalseTrue or False

Write each statement in your science Write each statement in your science notebook. If it is true leave it alone, if it is notebook. If it is true leave it alone, if it is false change it to make it true.false change it to make it true.1.1.The set of natural processes that form, The set of natural processes that form, change, and re-form rock is called the rock change, and re-form rock is called the rock cyclecycle2.2.Rocks and minerals are the same thing.Rocks and minerals are the same thing.3.3.Igneous rock develops from layers of Igneous rock develops from layers of sediment.sediment.

Mechanical & Mechanical & Chemical Forces Chemical Forces

break down break down RocksRocks

The BIG IdeaThe BIG Idea NATURAL FORCES BREAK ROCKS NATURAL FORCES BREAK ROCKS

APART AND FORM SOIL, WHICH APART AND FORM SOIL, WHICH SUPPORTS LIFE. SUPPORTS LIFE.

ThinkThink Imagine the Imagine the

tiniest rock you tiniest rock you have ever found. have ever found. How did it get so How did it get so small? It didn’t small? It didn’t start out that start out that way! What forces way! What forces created this created this rock? rock?

Mechanical Weathering Mechanical Weathering

The natural process of The natural process of mechanical weathering, physical mechanical weathering, physical forces split rocks apart but do not forces split rocks apart but do not change their composition (like change their composition (like smashing a walnut). smashing a walnut).

Ice Wedging Water freezes in Water freezes in

the cracks of rocks the cracks of rocks and expands. The and expands. The force of expansion force of expansion is strong enough is strong enough to split the rocks to split the rocks apart. This apart. This process can break process can break up huge boulders.up huge boulders.

Pressure ReleasePressure Release Earth’s forces can push Earth’s forces can push

rock that formed deep rock that formed deep underground up to the underground up to the surface. surface.

ExfoliationExfoliation The process The process

in which in which layers or layers or sheets of sheets of rock rock gradually gradually break off.break off.

Plant Root GrowthPlant Root Growth Trees, bushes and other plants Trees, bushes and other plants

may take root in cracks in rocks. may take root in cracks in rocks. As the roots grow, they wedge As the roots grow, they wedge the rocks open. the rocks open.

Tree Root GrowthTree Root Growth

Ruins of Ta Prohm, one of the temples of Ankor Wat

AbrasionAbrasion Water wears down rocks on riverbeds Water wears down rocks on riverbeds

and along shorelines by abrasion. and along shorelines by abrasion. The force of moving water alone The force of moving water alone causes this.. causes this..

Chemical WeatheringChemical Weathering Minerals in rocks Minerals in rocks

undergo chemical undergo chemical changes when they changes when they react with water react with water and air. and air.

Dissolving Dissolving Water is the main cause of Water is the main cause of

chemical weathering. Some chemical weathering. Some minerals can completely disolve minerals can completely disolve in water.in water.

RustingRusting

Oxygen, water, and dissolved Oxygen, water, and dissolved minerals containing iron produce minerals containing iron produce rust. rust.

Weathering occurs at Weathering occurs at different ratesdifferent rates Most weathering occurs over long Most weathering occurs over long

periods of time- hundreds, periods of time- hundreds, thousands, or even millions of thousands, or even millions of years. years.

Things that affect the Things that affect the rate of weatheringrate of weathering Surface Area-Surface Area- the more of a rock the more of a rock

that is exposed, the faster it will that is exposed, the faster it will show affects of weatheringshow affects of weathering

Rock Composition-Rock Composition- the harder the harder the rock, the slower it shows signs the rock, the slower it shows signs of weatheringof weathering

Climate-Climate- hot, wet regions weather hot, wet regions weather rocks faster than cold, dry ones rocks faster than cold, dry ones

QUESTIONSQUESTIONS

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