Science (2)

Question 1

What is a seismic wave?

Answer 1

Vibrations that travel through Earth carrying the energy released during an earthquake.

Question 2

What is the crust?

Answer 2

The layer of rock that forms Earth’s outer surface

Question 3

What is the mantle?

Answer 3

The layer of hot solid material between earth’s crust and core.

Question 4

What is the outer core?

Answer 4

A layer of molten iron and nickel that surrounds the inner core of Earth.

Question 5

What is the inner core?

Answer 5

A dense sphere of solid iron and nickel at the center of Earth.

Question 6

What is evidence?

Answer 6

Information or data used to support a conclusion.

Question 7

What is an element?

Answer 7

A substance that contains one kind of atom and cannot be broken down into simpler form.

Question 8

What is the lithosphere?

Answer 8

The crust and uppermost mantle make up the rigid lithosphere. The lithosphere rests on the softer material of the asthenosphere.

Question 9

What is the asthenosphere?

Answer 9

The solid yet bendable (less rigid) lower mantle that is directly beneath the lithosphere.

Question 10

What is a mineral?

Answer 10

A naturally occurring solid that can form by inorganic processes, and that has a crystal structure and definite chemical composition.

Question 11

What is a crystal?

Answer 11

A solid in which atoms are arranged in a pattern that repeats and repeats again.

Question 12

What is crystallization?

Answer 12

The process by which atoms are arranged to form a material that has a crystal structure.

Question 13

What is organic?

Answer 13

Related to living organisms.

Question 14

What is an igneous rock?

Answer 14

A type of rock formed from the cooling of molten rock at or below the Earth’s surface.

Question 15

What is a sedimentary rock?

Answer 15

A type of rock formed when particles of other rocks or the remains of plants and animals are pressed and cemented together.

Question 16

What is sediment?

Answer 16

Small, solid pieces of material that come from rocks or the remains of organisms; earth materials deposited by erosion.

Question 17

What is a metamorphic rock?

Answer 17

A type of rock formed from an existing rock that is changed by heat, pressure, or chemical reaction.

Question 18

What is apply?

Answer 18

To add force or to act on in order to cause change.

Question 19

What is the rock cycle?

Answer 19

A series processes on the surface and inside Earth that slowly changes rocks from one kind to another.

For example, the process of weathering breaks down granite into sediment that gets carried away and dropped by the wind, and some of that sediment can later form sandstone.

Question 20

What is process?

Answer 20

A series of changes that happen over time and lead to an expected result.

Question 21

What is source?

Answer 21

The place where something comes from; the point where something begins.

Question 22

How do geologists study the unseen interior of Earth?

Answer 22

They rely on direct evidence from rock samples and indirect evidence from seismic waves.

Question 23

How do geologists use rock samples to study Earth’s interior?

Answer 23

They drill deep into Earth to collect rock samples for clues about Earth’s structure and conditions deep inside where the rocks are formed.

Volcanoes sometimes carry rocks to the surface, which provide clues about how matter and energy flow there.

Some rocks from mountain ranges show evidence that they formed deep within Earth’s crust and later were elevated as mountains formed.

In laboratories, geologists have used models to recreate conditions similar to those inside Earth to see how those conditions affect rock.

Question 24

How do geologists use seismic waves to study Earth’s interior?

Answer 24

Geologists record and study the paths of seismic waves because they reveal where the makeup or form of the rocks change.

Question 25

What changes as you travel deeper to the Earth's core?

Answer 25

The pressure and temperature inside Earth increases as the depth increases.

Question 26

Where does the heat inside Earth come from?

Answer 26

Mostly the result of the release of energy from radioactive substances and heat left over from the formation of Earth billions of years ago.

Question 27

What is the composition of oceanic crust and continental crust?

Answer 27

The composition of all oceanic crust is much like basalt (dark, fine-grained rock), with small amounts of ocean sediment on top. The composition of continental crust is much like granite, a rock that usually is a light color and has coarse grains.

Question 28

Describe the mantle's layers starting from its upper layer.

Answer 28

Lithosphere: the uppermost layer of the mantle is brittle rock, like the rock of the crust. Both the crust and the uppermost part of the mantle are strong, hard, and rigid. Below the lithosphere is a solid yet bendable layer is called the asthenosphere, which is increasingly hotter and is therefore it is less rigid than the lithosphere. Below the asthenosphere is the lower mantle, which is hot, rigid, and under intense pressure. The lower mantle extends down to Earth’s core.

Question 29

What are the 2 layers of Earth's core?

Answer 29

A liquid outer core and a solid inner core. The outer core is a layer of molten metal surrounding the inner core. The inner core is a dense ball of solid metal.

Question 30

What is Earth's core made of?

Answer 30

Evidence suggests that both parts of the core are mostly made of iron and nickel, with smaller amounts of oxygen, sulfur, and silicon.

Question 31

Why is the inner core solid despite the extremely high temperatures?

Answer 31

Extreme pressure squeezes the atoms of iron and nickel so tightly that they cannot spread out to become liquid.

Question 32

Where do scientists think the Earth’s magnetic field comes from?

Answer 32

Scientists think that movements in the liquid outer core produce Earth’s magnetic field.

Question 33

What is convection? What are convection currents and how does it occur in the mantle?

Answer 33

The transfer of heat in the mantle drives a process called convection, which is how matter and energy cycle through Earth’s interior as well as its surface. Convection currents are the flows that transfer heat within matter. Convection occurs in the mantle because heat (a form of energy) transfers from matter at a higher temperature (the core) to matter at a lower temperature (the mantle), set in motion by gravity.

Question 34

Explain why convection currents are a never-ending cycle.

Answer 34

Heat from the core and from the mantle itself drives convection currents, which carry hot, solid rock of the mantle upward. As these are cooled, they go down to the mantle again to form never-ending cycle.

Question 35

What are the five essential characteristics for a solid to be classified as a mineral?

Answer 35

1) Naturally occurring 2) Solid 3) Forms by inorganic processes (they can form from materials that were not a part of living things) 4) Crystal structure 5) Definite chemical composition (it always contains the same elements in certain proportions)

Question 36

What are some properties that can be used to identify minerals?

Answer 36

Hardness, color, luster (how light reflects off the surface), streak (color of its powder), density, cleavage and fracture, crystal structure, and certain other special properties..

Question 37

What is an example of minerals forming by organic processes? Where does the energy come from to do so?

Answer 37

Animals such as cows and humans produce skeletons made of the mineral calcium phosphate. Ultimately, the energy used to drive the processes of mineral formation in most living things can be traced all the way back to the sun and the plants that use its energy.

Question 38

How do minerals form from dissolving water?

Answer 38

On Earth’s surface, energy from the sun can cause water to evaporate, leaving behind minerals. Minerals such as halite, calcite, and gypsum form through crystallization when bodies of water on Earth’s surface evaporate. Water below Earth’s surface can pick up elements and compounds from surrounding rock. When these elements and compounds leave the water solution through precipitation, crystallization can occur.

Question 39

How do minerals form from magma and lava?

Answer 39

When hot magma from Earth’s interior cools higher up in the crust, or as lava cools and hardens on the surface, they cool to a solid state and form crystals.

Question 40

How does the rate of cooling affect the formation of mineral crystals?

Answer 40

Slow cooling leads to the formation of large crystals, while fast cooling leaves very little time for crystals to grow. Lava cools quickly on the surface or under water and forms small crystals, such as pyroxene and fine-grained olivine in basalt rock of the oceanic crust.

Question 41

How does fast cooling affect the formation of mineral crystals?

Answer 41

**Fast cooling** of lava on the surface leaves very little time for crystals to grow

Question 42

What two forces/conditions can alter one mineral into a new mineral? Give an example.

Answer 42

A change of in temperature or pressure. Example: both graphite and diamonds are made of carbon, but graphite is soft while diamonds are extremely hard. Diamonds form beneath Earth’s surface within the mantle, where temperature and pressure are intensely high, which alter the structure of the carbon atoms in graphite to form diamond.

Question 43

What factors impact where and the number of minerals are found?

Answer 43

Common minerals that make up the rocks of Earth’s crust are found abundantly throughout Earth’s surface. Other minerals are much less common because their formation depends on more limited materials and conditions, or due to processes that take a very long time. Volcanic eruptions or evaporations in ocean basins can also cause certain minerals to collect in concentrated deposits.

Question 44

How do geologists describe rocks and classify their origin?

Answer 44

To describe rocks, geologists observe mineral composition, color, and texture. Mineral Composition and Color: about 20 minerals make up most of the rocks of Earth’s crust. These minerals are known as rock-forming minerals. A rock’s color provides clues to the rock’s mineral composition. Texture: to describe the texture of a rock, geologists use terms that are based on the size, shape, and pattern of the grains. Using mineral composition, color, and texture, geologists classify a rock’s origin (how the rock formed).

Question 45

What are the three major goups of rocks based on origin?

Answer 45

1) igneous rock 2) sedimentary roc 3) metamorphic rock.

Question 46

What is the source of igneous rock?

Answer 46

Cooled magma or lava. The temperature and composition of the molten rock determine the kind of igneous rock that is formed.

Question 47

What are the 2 different types of igneous rock? How are each of them formed?

Answer 47

Extrusive rock and intrusive rock. Extrusive rock is formed from lava that erupted onto Earth’s surface. Intrusive rock is formed when magma hardened beneath the surface of Earth

Question 48

What are the most common extrusive and intrusive rocks?

Answer 48

Basalt is the most common extrusive rock, making up a large part of oceanic crust. Granite is the most abundant type of intrusive rock in the continental crust. Granite forms tens of kilometers below Earth’s surface and over a long period of time. When granite ends up close to the surface, it may be mined for use as building materials.

Question 49

Describe the process where sediment forms and becomes sedimentary rock.

Answer 49

Sediment forms and becomes sedimentary rock through a sequence of weathering and erosion, transportation, deposition, compaction, and cementation.

Question 50

Where is most metamorphic rock formed, and why?

Answer 50

Metamorphic rock is changed by heat or pressure or by chemical reactions. Most metamorphic rock forms deep inside Earth where both heat and pressure are much greater than at Earth’s surface. Heat comes from hot mantle or magma that rises up into colder rock. The pressure comes from colliding plates or when rock is buried beneath millions of tons of rock.

Question 51

What is the one common force that drives all phases of the rock cycle?

Answer 51

Energy. No matter what type of rock is formed, it formed as a result of the energy that flows through the Earth system. The energy that drives forces affecting the formation of sedimentary rock (such as weathering, erosion, transportation, and deposition), comes in the form of heat from the sun. Heat from Earth’s interior drives the processes that control the formation of igneous and metamorphic rocks.

Question 52

What are the sources of energy that drive volcanic processes?

Answer 52

The energy comes primarily from the Earth's internal heat, generated by the planet's formation and the ongoing radioactive decay. This heat causes convection currents in the mantle, which move tectonic plates and lead to magma rising to the surface.

Question 53

Explain the basic difference between igneous and metamorphic rock.

Answer 53

The main difference is that igneous rocks form from the cooling and solidification of molten rock, while metamorphic rocks form when existing rocks are changed by intense heat, pressure, or chemical alteration without melting.

Question 54

True or false: there are a limited number of pathways for rocks to move through the rock cycle.

Answer 54

False. There are many pathways by which rocks move through the rock cycle. These pathways and the processes and events they include are patterns that repeat again and again.

Question 55

What are some of the major events that are involved in the rock cycle to change rocks from one type to another?

Answer 55

Melting, weathering, erosion, deposition, application of heat and pressure, and volcanic activity.

Question 56

Use granite as an example and trace how it goes through the rock cycle, starting from after it is formed.

Answer 56

After the granite formed, the forces of mountain building slowly pushes the granite up to the surface. At the Earth surface, weathering and erosion breaks down granite. Pieces of granite are then transported by streams as sediment to rivers and eventually to the ocean. Over millions of years, layers of sediment build up on the ocean floor, and the weight of the layers would physically compact the sediment. Then calcite in the ocean water could cement the particles together, causing a chemical change in the material. Over time, the material could become the sedimentary rock sandstone. The motion of Earth’s plates move the sandstone deeper below the surface, where higher pressure would compact them and cause physical and chemical changes so that some of the particles crystallize. After millions of years, the sandstone could change into the metamorphic rock quartzite. Or, the heat below Earth’s surface could melt the sandstone and form magma, starting the cycle over again.

Question 57

Describe how plate tectonics are involved in the rock cycle.

Answer 57

1) When oceanic plates move apart, magma moves upward and fills the gap with new igneous rock. 2) When an oceanic plate moves beneath a continental plate, magma also forms and rises, resulting in volcanic activity where lava flows out, forming igneous rock. 3) Sedimentary rock can also result from plate movement when the collision of continental plates is strong enough to push up a mountain range. Then, weathering and erosion wear away mountains and produce sediment that may eventually become sedimentary rock. 4) A collision between continental plates can push rocks down deep beneath the surface, where heat and pressure could change the rocks to metamorphic rock.

Question 58

True or false: as the rock in Earth’s crust moves through the rock cycle, no material is lost or gained.

Answer 58

True. No materials are lost or gained. Instead it changes form and gets recycled. For example, basalt that forms from hardened lava can weather and erode to form sediment. The sediment can eventually form new rock.