4th Grade Science

Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 1: What are minerals?

mineral

A mineral is a natural, nonliving, solid crystal that makes up rocks.

Oral Response Task Restate the definition of a mineral.

All over the world, each mineral has the same chemical makeup. Scientist have identified more than 3,000 minerals.

crystal

A crystal is a three-dimensional shape with flat surfaces.

Oral Response Task Describe a crystal.

To identify a mineral, scientists tests its properties, which include color, luster, hardness, cleavage, and crystal shape.

luster

Luster is the property of a mineral that describes how it reflects light.

Oral Response Task Explain the meaning of luster.

A glassy luster is shiny. A metallic luster looks like polished metal. A soft shine can be described as a waxy, silky, or pearly luster.

hardness

Hardness is a measure of how easily a mineral can be scratched.

Oral Response Task Describe hardness.

Diamond is the hardest mineral. It has a hardness of 10.

streak

Streak is the color of the powder that a mineral leaves when it is scratched across a special plate.

Oral Response Task Evaluate why different minerals have different streaks.

Sometimes the streak is a different color than the mineral itself. For example, hematite can be silver or red but its streak is always red.

cleavage

Cleavage is property of minerals that break along smooth, flat surfaces.

Oral Response Task Identify and describe the cleavage of a rock.

Some minerals do not have any cleavage. Quartz often breaks into pieces with smooth surfaces that look like the inside of a seashell.

4th Grade Science

Unit C: Earth Sciences Chapter 6: Minerals and Rocks

Lesson 2: How are minerals and ores sorted?

ore

Ore is a rock rich in valuable minerals that can be removed from Earth’s crust.

Oral Response Task Restate the definition of ore.

Ore deposits are not common everywhere in Earth’s crust. People use many different methods to find them.

copper

Copper is a soft metal that is a good conductor and is easy to shape, often to make wire.

Oral Response Task Describe copper.

Copper is a shiny metal that is easy to shape and to make into wire and pipes.

4th Grade Science

Unit C: Earth Sciences Chapter 6: Minerals and Rocks

Lesson 3: How are rocks classified?

igneous

Igneous describes a type of rock that forms from molten rock.

Oral Response Task Explain igneous rocks.

Igneous rocks for from molten rocks called magma. They can form above or below earth’s surface. Usually they are hard and they don’t have layers but they often have crystals that interlock.

lava

Lava is hot, molten rock that reaches Earth’s surface.

Oral Response Task Describe lava.

As the lava cools, mineral crystals form. However, when lava cools quickly, there is not time for the crystals to form.

magma

Magma is hot, molten rock that forms deep underground.

Oral Response Task Distinguish between magma and lava.

As magma raises slowly, it might melt some of the surrounding rock. The magma slowly cools and crystals of minerals form in the rock.

sedimentary

Sedimentary describes a type of rock that forms when layers of sediments settle on top of one another and harden.

Oral Response Task Describe sedimentary rocks.

Sedimentary rocks are made up of soil, shells, bits of rock, and the remain of dead plant and animal matter.

layering

Layering occurs when pressure on sediment that settles on top of older layers, creating newer layers.

Oral Response Task Explain the process of layering.

Layers of rock at Earth’s surface are usually younger than the layers below them. This fact helps scientists who study the ages of rocks as well as those who study things that have loved on Earth.

metamorphic

Metamorphic describes a type of rock formed when heat and pressure change the properties of rock.

Oral Response Task Describe metamorphic rocks.

Metamorphic rocks can form from sedimentary rocks, igneous rocks, and even other metamorphic rocks.

4th Grade Science

Unit C: Earth Sciences Chapter 6: Minerals and Rocks

Lesson 4: How do rocks change?

rock cycle

The rock cycle is the process that recycles rock into new types of rock.

Oral Response Task Examine the parts of the rock cycle.

Rocks are always changing from one form into another in a process called the rock cycle.

ash

Ash is finely pulverized lava thrown out by a volcano in eruption.

Oral Response Task Describe ash.

Ash from volcanoes forms layers of sediment.

4th Grade Science

Unit C: Earth Sciences Chapter 7: Our Changing Earth

Lesson 1: How does Earth’s surface slowly change?

landforms

Landforms are natural features of Earth.

Oral Response Task List the different types of Earth’s landforms.

Some landforms take shape quickly, but others take over a long time. A mountain may take millions of years to form, but rocks rolling down its side can change the mountain in a hurry.

weathering

Weathering is the process that breaks down rocks in Earth’s crust into small pieces.

Oral Response Task Describe the process of weathering.

Before landforms can change, the rocks that form them must first break apart. Weathering is the process that breaks rocks in Earth’s crust into small pieces.

4th Grade Science

Unit C: Earth Sciences Chapter 7: Our Changing Earth

Lesson 2: What causes physical weathering?

glaciers

Glaciers are huge moving sheets of ice.

Oral Response Task Restate the definition of glaciers.

Glaciers can cause physical weathering by creeping very slowly over land. As the glacier slides along, it drags rocks with it.

freezing

Freezing is approaching, at, or below the freezing point.

Oral Response Task Describe freezing.

When water freezes, it expands. Water from the rain or melted snow seeps into cracks in rocks. As the water freezes, the ice pushes against the sides of the crack. In time, the rock will split.

thawing

Thawing is to pass or change from a frozen state to a liquid state.

Oral Response Task Distinguish between thawing and

freezing.

Cycles of freezing and thawing cause rocks to split.

soil

Soil is the thin layer of loose, weathered material that covers most of the land surface of Earth.

Oral Response Task Describe soil.

Weathering breaks rocks into small pieces that are ingredients in soil.

4th Grade Science

Unit C: Earth Sciences Chapter 7: Our Changing Earth

Lesson 3: How does weathered material move?

erosion

Erosion is the movement of weathered materials.

Oral Response Task Illustrate the process of erosion.

Wind, water, glaciers, living things, and gravity cause erosion.

transport

Transport is to carry from one place to another.

Oral Response Task Analyze the effects of transport in the process of erosion.

Water often carries, or transport, weathered materials from one place to another.

gravity

Gravity is the force of attraction toward the center of the Earth.

Oral Response Task Appraise the importance of gravity.

Gravity pulls rocks and soil downhill.

deposition

Deposition is the laying down of piece of rock and soil.

Oral Response Task Assess the effects of deposition in the process of erosion.

Water flowing quickly carries large particles . As the moving water slows, the large particles as well as sand are deposited at the bottom.

4th Grade Science

Unit C: Earth Sciences Chapter 7: Our Changing Earth

Lesson 4: What causes rapid changes to landforms?

landslide

A landslide is the rapid downhill movement of large amounts of rock and soil.

Oral Response Task Describe a landslide.

Landslides can cause a lot of damage. Buildings, cars, trees, and other objects are sometimes carried along with the sliding soil.

volcano

A volcano is place on Earth’s crust where magma reaches the surface.

Oral Response Task Question the process by which a

volcano erupts.

The volcano erupts when the magma reaches the surface

dormant

Dormant describes a volcano in a state of rest.

Oral Response Task Describe a dormant volcano.

A volcano that has not erupt for a long time is said to be dormant.

active

Active describes a volcano that has frequent eruptions or shows signs of future eruptions.

Oral Response Task Distinguish between an active volcano

and a dormant volcano.

An active volcano has frequent eruptions or shows signs of future eruptions.

fault

A fault is a break or crack where Earth’s crust can move.

Oral Response Task Describe a fault.

Sometimes, rocks along a fault can get stuck. The plates however, continue their slow movement, or creep.

earthquake

An earthquake is a sudden movement that causes Earth’s crust to shake.

Oral Response Task Describe what happens to the Earth during an earthquake.

The vibrations of an earthquake move as waves that travel through Earth.

plates

Plates are large pieces of the Earth’s crust.

Oral Response Task Propose an explanation to the Earth’s crust being broken into plates.

Two plates meet along the San Andres fault.