7Th Grade Knowledge Map 2014-2015

7th grade Knowledge Map 2014-2015

Quarter 1

Chapter 1 – Scientific Thinking

A quantitative observation deals with numbers, or amounts.
A qualitative observation deals with descriptions that cannot be expressed in numbers.
When you explain or interpret the things you observe, you are inferring.
Evaluating involves comparing observations and data to reach a conclusion about them.
Making models involves creating representation of complex objects or processes.
Skepticism is having an attitude of doubt. Skepticism keeps a scientist from accepting ideas that may be untrue.
Ethics refers to the rules that enable people to know right from wrong.
Personal bias comes from a person’s likes and dislikes.
Cultural bias stems from the culture in which a person grows up.
Experimental bias is a mistake in the design of an experiment that makes a particular result more likely.
Being objective means that you make decisions and draw conclusions based on available evidence.
Being subjective means that personal feelings have entered into a decision or conclusion.
The seven steps of the scientific method are ask a question, make observations, form a hypothesis, test the hypothesis, analyze results, draw conclusions, communicate results.
A controlled experiment is an experiment that tests only one factor at a time by using a comparison of a control group with an experimental group.
A variable is a factor that changes in an experiment in order to test a hypothesis.
The one variable that is purposely changed to test a hypothesis is the independent (manipulated) variable.
The factor that may change in response to the independent variable is the dependent (responding) variable.
Data are the facts, figures, and other evidence gathered through qualitative and quantitative observations.
A scientific theory is a well tested explanation for a wide range of observations and experimental results.
A scientific law is statement that describes what scientists expect to happen every time under a particular set of conditions.

Chapter 2 – Using Math in Science

The International System of Units is important because it gives all scientists a standard set of measurements to use in order to share and compare their observations and results.
In SI, the basic unit for measuring length is the meter (m).
Mass is a measure of the amount of matter in an object.
In SI, the basic unit for mass is the gram (g).
Weight is a measure of the force of gravity acting on object. Its value can change with the location of the object in the universe.
Volume is the amount of space an object or substance takes up. In SI, the basic unit for measuring volume of a liquid is the liter (L). In SI, the basic unit for measuring volume of a solid is the cubic meter (m3).
Density is the ratio of the mass of a substance to the volume of substance. In SI, the basic unit for density is the gram per cubic centimeter (g/cm3).
The common unit for temperature is Celsius (°C). On the Celsius scale, water freezes at 0° C, and boils at 100° C.
Accuracy refers to how close a measurement is to the true or accepted value.
Precision refers to how close a group of measurements are to each other.
The significant figures in a measurement include all digits measured exactly, plus one estimated digit.
Percent error calculations are a way to determine how accurate an experimental value is.
The mean is the numerical average of a set of data.
The median is the middle number in a set of data.
The Mode is the number that appears most often in a list of numbers.
The range of a set of data is the difference between the greatest value and the least value in the set.
Data that do not fit with the rest of the data set are anomalous data, or outliers.
Line graphs display data that show how one variable (the dependent variable) changes in response to another variable (the independent variable).
To calculate slope divide the rise by the run.
A system is a group of parts that work together to perform a function or produce a result.

Quarter 2

Chapter 8 – Introducing Earth

The Earth’s system has four main spheres: the atmosphere, the hydrosphere, the geosphere, and the biosphere.
Lands are constantly being created and destroyed by competing forces: constructive and destructive.
The crust, or lithosphere, is a layer of solid rock that includes both dry land and ocean floor.
The mantle is made of melted rock and is the thickest layer of the three.
The core is divided into two layers: a liquid outer core and a solid inner core.
The Earth possesses a magnetic field that is detectable at the surface with a compass.
Convection currents in the mantle cause lithospheric plates to move causing fast changes like earthquakes and volcanic eruptions, and slow changes like creation of mountains and formation of new ocean floor.

Chapter 9 - Rocks and Minerals

A mineral is a naturally occurring solid that came from inorganic processes and that has a crystal structure and definite chemical composition.
Each mineral can be identified by the following: color, streak, luster, hardness, cleavage and fracture.
Two characteristics used to classify rocks are composition and texture.
An igneous rock forms from the cooling of magma or lava.
Intrusive igneous rock is formed from the cooling and solidification of magma beneath the Earth’s surface.
Extrusive igneous rock is formed as a result of volcanic activity at or near the Earth’s surface.
Sedimentary rocks are formed when small particles of rocks or the remains of plants and animals are pressed and cemented together.
Most sedimentary rocks are formed through the following: weathering, erosion, deposition, compaction, and cementation.
Metamorphic rocks form when a rock is changed by heat or pressure.
The rock cycle occurs through forces deep inside Earth and at the surface that produce a slow cycle that builds, destroys and changes rocks.

Chapter 14: A trip through Geologic Time

Fossils form when living things die and are buried by sediment.
Fossils can be preserved in rocks, amber, asphalt, ice, and through petrifaction
The fossil record provides evidence about the history of life and past environments on Earth. The fossil record also shows how different groups of organisms have changed over time.

Superposition is a principle that states that younger rocks lie above older rocks if the layers have not been disturbed. (Younger over older)
Index fossils are useful because they tell the relative ages of rock layers in which they occur.

Gaps in the geologic record along with folding can change the position in which rock layers appear.
Because the time span of Earth’s past is so great, geologist use the geologic time scale to show Earth’s history.
The geologic time scale is a record of the geologic events and the evolution of life forms as shown in the fossil record.
The geologic time scale is the standard method used to divide the Earth’s long natural history into manageable parts, such as eras and epochs.

Chapter 10: Plate Tectonics

Mid-ocean ridges from long chains of mountains that rise up from the ocean floor.
Sea-floor spreading adds more crust to the ocean floor. At the same time, older strips of rock move outward from either side of the ridge.
Through the process of subduction, which takes millions of years, part of the ocean floor sinks back into the mantle.
Earth’s plates meet at three types of boundaries:convergent, divergent, transform.
The theory of plate tectonics states the Earth’s plates are in slow, constant motion, driven by convection currents in the mantle.

Chapter 11: Earthquakes and Volcanoes

Stress is a force that acts on rock over millions of years to change the shape and volume of rock. There are three kinds of stress: tension, compression, and shearing.
When stress builds up in rock, the rock breaks creating a fault.
There are three types of faults: normal, reverse, strike-slip.
Over millions of years, the forces of plate movement can change a flat plain into features such as anticlines and synclines, folded mountains, fault-block mountains and plateaus.
Seismic waves are vibrations that are similar to sound waves. They travel through the Earth carrying energy released by an earthquake.
P waves, aka pressure waves, are the fastest. S waves, aka shear waves are the second fastest. Surface waves are the slowest but most destructive.
The amount of damage from an earthquake or shaking that is felt is rated using the Modified Mercalli scale.
The magnitude or size of an earthquake is measured on a seismograph using the Richter scale or moment magnitude scale.
Geologist use seismic waves to locate an earthquakes epicenter.
Volcanoes are mountains that forms in Earth’s crust when molten material, or magma reaches the surface.
The Ring of Fire, is one major belt of volcanoes and earthquakes.
Magma is molten mixture of rock forming substances, gases and water from the mantle. When magma reaches the surface it is called lava.
Geologists classify volcanic eruptions as explosive and nonexplosive, (or quiet) depending in part on the magma’s silica content and the viscosity of the magma.
Geologists often use the terms active, dormant or extinct to describe a volcanoes stage of activity.
Magma erupts as either lava or pyroclasitc material.

There are three types of volcanoes: Shield, Cindercone, and composite.

Quarter 3

Chapter 3: Forces and Motion

When an object changes position over time relative to a reference point, the object is in motion.
Speed is the distance traveled by an object divided by the time taken to travel that distance.
Average speed is the total distance traveled divided by the total time.
Instantaneous speed is the speed at which an object is moving at a given instant in time.
Velocity is the speed of an object in a particular direction.
Acceleration is the rate at which velocity changes over time.
Average acceleration is equal to the final velocity minus the starting velocity all divided by the time it takes to change velocity.
A force is a push or pull; all forces act on objects.
The strength of a force is measured in the SI unit called the Newton, (N) after scientist Sir Isaac Newton.
Net force is the combination of all the forces acting on an object.
If the forces are acting in the same direction, the forces are added together to determine net force on the object. If the forces are acting in opposite directions, the forces are subtracted to determine net force.
When net force equals zero, the forces are said to be balanced.
If the net force is not equal to zero, the forces are said to be unbalanced and therefore a change in motion has occurred.
Friction is a force that opposes motion between two surfaces that are in contact.
Two factors that affect the force of friction are the types of surfaces involved and how hard the surfaces are pushed together.
There are four types of friction; sliding friction, static friction, fluid friction and rolling friction.
Gravity is the force of attraction between two objects that is due to their masses.
Inertia is the tendency of all objects to resist any change in motion.
Newton’s first law of motion states that objects in motion stay in motion and objects at rest stay at rest unless an outside force acts upon them.
Newton’s second law of motion states that the acceleration of an object depends on the mass of the object and the amount of force applied.
Newton’s second law can be expressed mathematically by the equation: F = m x a, force equals mass multiplied by acceleration.
Newton’s third law of motion states that if one object exerts a force on another object, then the second object exerts a force equal in strength but in the opposite direction of the first.

Chapter 4: Energy and Energy Transfer

Energy is the ability to do work, and can be classified into two general types: kinetic and potential energy.
Kinetic energy is the energy of motion and depends on the objects mass and speed.
The formula for kinetic energy is KE = (mv2 ) ÷ 2where m stands for the mass of the object in kilograms, v stands for the object’s speed
Potential energy is energy that is stored as a result of position or shape, and depends upon the objects mass and height.
The formula for potential energy (GPE) is PE= weight x height . or PE= mgh
Mechanical energy is the form of energy associated with an object’s motion, position, or shape.
The formula for mechanical energy is the sum of potential and kinetic energy.
There are several other forms of energy such as: elastic potential energy, thermal, chemical, electrical, electromagnetic and nuclear.
The law of conservation of energy states that energy cannot be created or destroyed but can be converted from one form to another.
Convection is a type of circular motion heat transfer that occurs only in fluids such as air and water.
Radiation is the transfer of energy by electromagnetic waves.

Conduction transfers heat from one particle of matter to another within an object or between two objects.

Chapters 6/7: Sound and Light Waves

A sound wave is a longitudinal wave that is caused by vibrations and that travels through a medium.
A medium is a material through which a waves travels.
Waves that require a medium to travel through are called mechanical waves.
The three types of mechanical waves are transverse waves, longitudinal waves and surface waves.
The amplitude is the largest distance the particles in a wave vibrate from their rest positions.
Larger amplitude equals a louder sound.
High frequency equals a high pitch; low frequency equals a low pitch.
The speed of sound depends on the temperature, stiffness, and density of the medium it travels through
The speed of a wave can be calculated by multiplying the wavelength and frequency.
Reflection is when a wave cannot pass through a surface and bounces back.
Refraction is the bending of waves due to a change in speed.
A standing wave is a wave that appears to be standing in place, even though it is really two waves inferring as they pass througheach other.
Diffraction is when a wave moves around a barrier or through an opening in a barrier.
Interference is the interaction of waves that meet. There are two types of interference, constructive and destructive.
Sound is a vibration that travels through a medium as a longitudinal wave.
Pitch describes how high or low a sound is perceived.
The loudness of a sound waved depends on the energy and intensity of the sound wave. Loudness is measured in decibel (dB)
The Doppler effect is an observed change in the frequency of a wave when the source or the observer is moving.
An electromagnetic wave is made up of vibrating electric and magnetic fields that move through space or a medium at the speed of light.
Radiation is the transfer of energy through an EM wave.
Visible light is the only range on the EM spectrum that we can see.
Opaque objects get their color only from the light that is reflected.
Transparent and translucent objects get their color from the light that is transmitted.

The electromagnetic spectrum includes all of the frequencies or wavelengths of electromagnetic radiation.

Quarter 4

Chapter 5: Energy Resources

A natural resource is any natural material that is used by humans such as water, petroleum, minerals, forests, and animals.
A renewable resource is a natural resource that can be replaced at the same rate at which the resource is consumed.
A nonrenewable resource is a resource that forms at a rate that is much slower than the rate at which it is consumed.
A fossil fuel is a nonrenewable energy resource formed from the remains of organisms that lived long ago.
The three types of fossil fuels are oil, coal, and natural gas.
Seven types of alternative energy are nuclear energy, chemical energy, solar energy, wind power, hydroelectric energy, biomass, and geothermal energy.

Efficiency is the percentage of energy that is actually used to perform work.

Chapter 12: Weathering and Soil

Erosion works continuously to weather and carry away rocks at Earth’s surface.
There are two types of weathering: mechanical and chemical.
The agents of mechanical weathering include freezing and thawing, release of pressure, plant growth, actions of animals and abrasions.
The agents of chemical weathering include water, oxygen, carbon dioxide, living organisms and acid rain.
Soil is a mixture of rock particles, minerals, decayed organic material, water and air.
The fertility of soil is a measure of how well the soil supports plant growth.
Soil can be conserved through practices such as contour plowing, conversation plowing and crop rotation.

Chapter 13 Erosion and Deposition

The different types of mass movement include landslides, mudflows, slump and creep.
Moving water is the major agent of the erosion that has shaped Earth’s land surface.
Through erosion, a river creates valleys, waterfalls, flood plains, meanders, and oxbow lakes.
Deposition creates landforms such as alluvial fans and deltas.
Groundwater can cause erosion through a process of chemical weathering.
Glaciers can form only where more snow falls than melts, and can flow in all directions as they move.
The two processes by which glaciers erode the land are plucking and abrasion.
When a glacier melts, it deposits the sediment it eroded from the land, creating various landforms.
Waves shape the coast through erosion by breaking down rock and moving sand and other sediment.
Wind can be a powerful force in shaping the land in areas where there are few plants to keep the soil in place.

Chapter 15: Cells and Human Body Systems

The cell theory states the following: all living things are made of cells, cells are the basic unit of structure and function, and all cells are produced from other cells.
Diffusion is the movement of particles from areas of higher concentration to areas of lower concentration.
Osmosis is the diffusion of water through a semipermeable membrane.
Advantages of being a multicellular organism include larger size, longer life, and cell specialization.
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food.
Cellular respiration is the process by which cells use oxygen to produce energy from food.
Proteins are molecules that are made up of amino acids and that are needed to build and repair body structures and regulate processes in the body.
Carbohydrates are a class of energy giving nutrients that includes sugars, starches, and fiber.
Lipids are a type of biochemical that do not dissolve in water (like fats and steroids).
A phospholipid is a lipid that contains phosphorus and that is a structural component in cell membranes.
Adenosine triphosphate (ATP) is a molecule that acts as the main energy sources for cell processes.
Nucleic acids are molecules made up of subunits called nucleotides.
DNA is the genetic material that carries information about an organism and is passed from parent to offspring.