Oxford Class Midterm Exam (Science)

• Soil is also known as dirt.
• Consists of loose rock and decaying plant and animal material.
• Plants and animals decay by breaking apart, or rotting.
• Many organisms rely on soil.
• Animals and people need plants that grow in soil as a food source.
• Soil contains nutrients for plant survival.
• Plants can grow in loose soil or rock cracks.

Parts of Soil

• Consists of small bits of broken rock, humus, water, and air-filled spaces.
• Leaves fall from trees, turn brown, and dry out.
• Leaves crumble into smaller pieces and become part of the humus in the soil.
• Humus consists of the remains of dead and decaying living things.
• Plants and animals decay and become part of the soil over time.
• The soft, dark part of the soil, humus contains many nutrients needed for plant survival.
• Soil retains water and air in addition to humus.
• Plants need both water and air to grow.
• Plants require varied amounts of humus, water, and air to survive.
• The Earth contains various soil types to support different types of plants.

Layers of Soil

• Soil is formed in layers with the top layer being most visible.
• Topsoil contains the most humus.
• Most plants grow in the topsoil layer.
• Subsoil contains larger rock pieces and less humus than topsoil.
• Bedrock is the bottom layer of large, unbroken rock under the subsoil.

Weathering, Erosion, and Conservation

• Earth's surface is always changing, sometimes quickly, sometimes slowly and is part of God's plan.
• Large rocks break into smaller pieces, eventually becoming tiny pieces that become part of the soil.
• Flowing water, wind, ice, and plants cause rocks to break apart.
• The breakdown of rocks into smaller pieces = weathering.
• Water and wind moving rocks and soil = erosion.
• Flowing water weathers and erodes rocks, wearing away sharp edges.
• The water carries away broken rock bits, which then become part of the soil
• Weathering and erosion help to renew the soil.
• Fast flowing water changes the earth's surface.
• Floods can cover parts of the ground that are usually dry.
• Topsoil may not absorb all the water when it rains quickly.
• Floodwaters can erode rocks and soil.
• Landslides include heavy rain and flooding and is the rapid downhill movement of rocks and soil.
• Gravity pulls rocks and soil down a mountain/hill.
• Landslides erode large areas of earth's surface quickly.
• Wind weathers and erodes rocks, blowing sand rubs the rocks eventually wearing away bits.
• Plant roots help keep topsoil in place.
• Weathered bits of rock become part of the soil.
• Wind erodes loose topsoil.

Ice and Plants

• Ice and plants weather rocks.
• When water flows into rock cracks and freezes, it expands pushing the rock apart and breaking it into pieces.
• Over time, plants can weather rocks, even small plants.
• A plant growing from a seed in a rock pushes with great force as its roots and stem get larger.
• The growing plant can weather or break the rock into pieces.
• The broken rock is eroded by flowing water or wind, becoming part of the soil.

Conservation

• Soil is a natural resource, which is anything in nature God made for people to use.
• Conservation means taking care of and wisely using natural resources.
• Planting trees helps to conserve soil.
• Tree roots hold the soil in place.
• Trees around a field can slow or stop wind erosion.
• Trees and shrubs on a hillside can prevent landslides.
• Slowing or stopping erosion cares for the soil.
• Soil should be used wisely and soil that has not been polluted, has many important uses.
• Soil is used to grow food for people and animals.
• Some plants grown in soil can be used for medicine.
• Some types of soil make bricks for homes and walkways.
• Soil can be used make roads, plates and cups.

Rocks

• Rocks are hard pieces of the earth's surface made by God and some formed during the Genesis Flood, and some can even form today.
• Rocks come in many sizes and shapes.
• Scientists classify rocks into three groups: Sedimentary, igneous, and metamorphic rocks.

Sedimentary Rock

• Water and wind weather and erode pieces of rock.

• Small bits of weathered rock = sediment.

• Sedimentary rock forms when layers of sediment are pressed together and harden.

• Sedimentary rock can often be seen pieces of other rocks in it because sedimentary rock is made of sediment.

• Many different kinds of sedimentary rock exist and come from the different things mixed into rock.

• Limestone forms mainly from the shells of sea animals.

• Animal shells break apart and form limestone over time

• Sandstone is a sedimentary rock made when layers of sand are pressed together.

• Shale forms from mud layers.

Igneous Rock

• Forms when melted rock cools.
• Melted rock = very hot liquid deep beneath the earth
• Volcano = opening in the earth that allows melted rock to come to the surface.
• Lava is the melted rock that comes from out of a volcano.
• Lava cools and hardens and forms smooth rocks when cools quickly, and rough rocks when cools slowly.
• Obsidian is a smooth, glass-like igneous rock.
• Granite forms when melted rock cools slowly.
• Granite is often speckled, has shiny crystal spots, and a rough surface.
• Some mountains are made of granite.

Metamorphic Rock

• Metamorphic rock forms when igneous or sedimentary rocks are changed by great heat and pressure.
• Limestone is a soft sedimentary rock that becomes marble under heat and pressure.
• Artists often use beautiful and hard marble .
• Slate forms from shale and can be split into thin sheets.
• Landscapers use slate for walkways and yard decorations.
• Also used as roofing material.
• Heat and pressure can change granite into gneiss and is often used as a building material
• Rocks always change and break down into smaller rocks and melted rock changes to solid rock.

Minerals

• All rocks are made of one or more minerals.
• Are solid materials in nature that were never alive.

Properties of Minerals

• Minerals are not all alike and can be hard or soft.
• The hardness of a mineral can be tested, and this is one way that scientists can identify minerals.
• Friedrich Mohs created the Mohs Hardness Scale that ranks minerals from 1 to 10(softest to hardest), to test minerals.
• A scratch test finds out how hard mineral is.
• A harder mineral can scratch a softer one.
• Talc (1) is a very soft mineral that makes powder. and can be scratched by most minerals.
• Diamonds (10) are very hard, and can cut or scratch all other minerals.
• Most minerals form crystals.
• Crystal is a solid material whose particles are in a special pattern.
• Each mineral has its own crystal shape.
• The crystal's shape can help scientists know what mineral it is.

Color and Streak

• Minerals are different colors, but some minerals can look alike.
• Scientists use a streak test to identify a mineral.
• Scientists rub the mineral on a light-colored tile and the color of the streak on the tile helps them know what mineral it is.
• Gold and iron pyrite look alike.
• A streak test tells them apart.
• Gold leaves a yellowish streak.
• Iron pyrite leaves a greenish-black streak.

Uses of Minerals

• Minerals are used in many ways.
• Breakfast cereals contain iron which is a mineral.
• Iron helps the body work properly.
• Calcium is another mineral.
• Milk is a source of calcium.
• Hard-to-find minerals are considered precious minerals.
• Gold and silver are two precious metal minerals.
• Cut and polished crystals of some precious minerals are called gems.
• Diamonds are precious metals and gems that are often used in jewelry and drills.
• Easier-to-find minerals are common minerals.
• Halite, graphite, and quartz are common minerals.
• Salt comes from the mineral halite.
• The "lead" in pencils is a mixture of clay and the mineral graphite.
• Quartz is one of the most common minerals and makes most sand.
• This mineral makes glass, computers, and cell phones.
• Knowing how to use precious and common minerals helps people manage the earth as God commanded.

Fossils

• A worldview is how someone thinks about and understands the world.
• Scientists use their beliefs to explain observations.
• A person with a biblical worldview believes the Bible is true because it is God's Word and views fossils differently.
• A fossil is the remains or trace of a dead organism and form when organisms are buried quickly where the soft parts decay first.
• The harder parts can sometimes be seen as fossils.
• A mark made by a living thing becoming a fossil = trace fossils.
• Most fossils are found in sedimentary rock.
• Scientists with a biblical worldview believe most fossils formed during the Flood.
• The Flood occurred about 5000 years ago, wearing away soil and rocks quickly, developing a lot of sediment in a short amount of time.
• The Flood waters moved large amounts of sediment, burying living things not on the ark.
• As the water dried up, the sediment settled into rock layers.
• Scientists with a biblical worldview believe fossils in sedimentary rock support a worldwide Flood.
• Minerals helped some fossils form and took the place of the smallest parts of remains of plants and animals, turning the remains into rock.
• Petrified wood forms when a tree is buried quickly by sediment during a flood and the minerals turn the remains of the tree into rock.
• Quartz is a common mineral in petrified wood.
• Fossils of fish and seashells have been found on land and mountains.
• Flood waters covered entire earth and buried sea animals at high altitudes.
• Buried remains then turning to rock quickly.

Extinction

• After the Flood, the earth changed and some plants/animals could not survive and grow in the changed environment.
• Environment = all the living and nonliving things around a plant/animal.
• Some plants/animals became extinct = none of that kind are still alive.
• The shapes of original plants/animals have been preserved as rock.

Adaptation

• After the Flood, many plants and animals that survived were able to adapt, or change, to the changed world.
• Adaptation is a characteristic, or feature, that helps a living thing survive in its environment passed down from parents to offspring.
• God made all plants/animals to create more plants/animals "after their kind".
• God created living things with the ability to adapt.
• A snowshoe hare has fur that changes color so it can blend in for winter survival.
• Some animals became extinct.
• Evolution teaches that living things change by chance over millions of years, becoming new kinds of living things.

Evolutionary View of Fossils

• Fossils formed when living things were buried quickly, which did not decay or rot.
• Fossils formed at different times in the past after they were layered in sedimentary rock, over millions of years.
• Fossilized fish and seashells on mountains formed when sea animals were buried quickly at the bottom of rivers, lakes, or oceans.
• Over millions of years, the ocean floor was pushed up, and created mountains.
• Evolution tries to explain extinct plants/animals and believes adaptation results in one kind of animal evolving or changing, into another kind of animal over millions of years.
• Scientists that believe in evolution do not think that God created all things or made each kind of plant and animal.
• They think that one kind of animal evolved from another and created the lizards to only make more lizards.

Is Evolution True?

• A scientist also may not believe in the Genesis Flood or connect fossils with the Flood.
• But evolution is not true because evolution is not based on the Bible.
• The Bible is true because it is God's Word.