Federal Way Public Schools - Every Student...A Reader

Science

Draft - Updated 6/13/01

8th grade

Life Science

1. The student understands and uses scientific concepts and principles.

Human Biology

The human organism sustains life through its interconnected systems, for example the digestive, respiratory, circulatory, excretory, immune, reproductive, skeletal, muscle, nervous and endocrine systems.
The body uses food for energy and to obtain molecules for growth and development. Food is digested into molecules that are absorbed and transported to cells by the circulatory system. Oxygen is needed in cells to burn food to release the energy stored in it.
The respiratory system takes in air (uses oxygen for food combustion) and eliminates carbon dioxide as a byproduct.
Human wastes are disposed of by several systems. The excretory system disposes of the dissolved waste molecules in urine, and the digestive system is involved in the elimination of solid wastes. Excess body heat is released through the skin and breathing, and carbon dioxide is released through the respiratory system. In the kidneys, the process of active transport uses energy to pump some molecules against a concentration gradient (lower to higher concentration).
The circulatory system moves food, water, dissolved wastes, oxygen, and carbon dioxide to or from cells to meet body needs. These molecules diffuse across cellular membranes (in the case of water, it is referred to as osmosis) due to concentration gradients (higher to lower concentration). The four chambered heart acts as a pump and keeps the blood flowing in a continuous closed pathway(aorta, pulmonary artery, arteries, capillaries, veins, vena cava, pulmonary vein) throughout the body.
Disease involves a breakdown in an organism's structures or functions. Some diseases are the result of intrinsic failures of one or more of the body's systems. Other disease conditions are the result of damage by infection by microorganisms. Specialized cells and the molecules they produce identify and destroy microbes that get inside the body.
Hormones are chemicals from glands that affect other body parts. They are involved in helping the body respond to danger and in regulating human growth, development, and reproduction. Interactions among the senses, nerves, and brain sustain and coordinate human life functions. Sense organs enable human beings to monitor what is going on in the world around them, and to cope with changes in their environment.
Fertilization occurs when sperm cells from a male's testes are deposited near an egg cell from the female ovary, and one of the sperm cells enters the egg cell. Most of the time, by chance or design, a sperm never arrives or an egg isn't available.
Following fertilization, cell division produces a small cluster of cells that then differentiate by appearance and function to form the basic tissues of an embryo. During the first three months of pregnancy, organs begin to form. During the second three months, all organs and body features develop. During the last three months, the organs and features mature enough to function well after birth. Patterns of human development are similar to those of other vertebrates.

Physical Science

Forces to explain motion

1.1 Understand the effects of balanced and unbalanced forces on the motion of objects along a straight line.

If an object is not moving, the forces acting on it are balanced.
An object moving in a straight line will change speed (accelerate), if an unbalanced force acts on it.
A change in an object's speed is proportional to the unbalanced force acting on it and the time interval during which the unbalanced force is applied. Also, doubling or tripling the mass of the object will half or third the change in speed, other factors being kept the same.

Nature of forces

1.2 Know the factors that determine the strength of various forces.

Force is always an interaction between two objects. One object cannot push on a second without the second object pushing back.
Every magnet has magnetic north and south poles. Like poles repel each other and opposite poles attract each other.
The force that one magnet exerts on another is increased by increasing the strength of each magnet and is weakened by increasing the distance between them.
The electrical force of one charged object on another is increased by increasing the electrical charge on either or both objects, and is reduced by increasing the distance between the charged objects.
Every object exerts a gravitational force on every other object. This gravitational force is weak and hard to detect, unless one of the objects has very sensitive equipment. Gravitational force is strengthened as the mass of one or both objects increases. Widening the distance of separation between the objects and/or decreasing the mass of one or both objects decreases gravitational force.
Magnets and moving electrical charges (electrical current) can exert a force on each other. This force is increased by increasing the electrical current and/or by increasing the strength of the magnet. The force is decreased by increasing the distance between the current and the magnet.

Motion of objects

1.3 Describe the positions, relative speeds, and changes in speed of objects.

Words, graphs, tables, and pictures (strobe-like) are used to represent the position or speed of an object at any time during the story.
From representations of position vs. time, the average speed is determined by measuring or calculating how far the object travels in each one unit of time, and the speed is expressed in units, such as meters traveled for each one second (m/sec), centimeters per minute, miles per hour, or inches per year.
An object might move through a time interval at a constant speed or the speed might vary considerably, but in either case if the object had traveled the same distance, its average speed would have been the same (same distance divided by the same time).
Whether an object is speeding up, slowing down, or moving with constant speed can be determined by determining and comparing the relative speeds during those intervals.
Determine the speed at any instant and the change in speed for any time interval from representations (graphs, tables, speedometer pictures) of speedometer readings vs. time.
Determine whether an object is speeding up, slowing down, or moving at a constant speed, using representations of speedometer readings vs. time.

1.4 Describe the average speed, direction of motion, and average acceleration of objects.

Estimate the average speed and identify the direction of motion of objects during short intervals, for examples: one can estimate that the runner went 700 meters west in about 17 seconds, so averaged about 9 m/s toward the west, or an ant that jerkily moves along about 160 cm in 2 minutes had an average speed of 80 cm/s toward the end of the driveway
Determine an object's average speed and direction of motion for any interval of time, from graphs, pictures, or tables of position vs. time.
Define the average acceleration of an object traveling in one direction by determining the change in the object's instantaneous speedometer reading and dividing by the elapsed time associated with the change.
Determine the average acceleration of an object for any interval of time, during which the object is moving in a straight line, using data from graphs, pictures, or tables of instantaneous speed vs. time.

Properties of Substances

1.5 Use physical and chemical properties to identify and describe substances, for example density, boiling point and solubility.

Appropriately use physical properties, including density, boiling point, freezing point, and solubility to identify or describe particular substances.
Appropriately use chemical properties, including pH and reactivity to describe substances.
Operationally define, measure, and use appropriately the ideas of length, area, and volume to describe the size of objects.
Differentiate between operations to obtain measures of mass (equal arm balance), weight (spring scale), and density (mass associated with each one unit of volume, e.g., the number of grams of substance for each one cubic centimeter of the substance). For a given substance, the density is the same number, regardless of the amount of substance. Thus, density is a property of the particular kind of substance.

Physical/Chemical Changes

1.6 Understand physical and chemical changes at the particle level, and know that matter is conserved. 0r Know about physical and chemical changes at the particle level, and know that matter is conserved.

Particles in a solid vibrate rapidly, are close to each other, and are usually arranged in an orderly, repeating pattern. Thermal energy transferred to a solid will cause particles to vibrate more quickly and farther. The result may be that the solid material expands, or the molecules may break out of their regular fixed positions, and cause a physical change such as melting.
Particles of a substance in a liquid state move more rapidly than the particle movement in the solid state, but slower than in the gaseous state. In a liquid the particles are only loosely connected and can slide past each other, but there is very little empty space between molecules in a liquid. Liquids expand and contract only slightly (compared to gases) under the influences of changes in temperature or pressure. Heat applied to a liquid will cause particles to move more rapidly and slightly farther apart from each other. Part of the evidence for movement of liquid molecules is diffusion. For example, a drop of food coloring eventually spreads evenly throughout a glass of water.
When particles in a container are free to move, they collide with the walls of the container. The faster the particles are traveling and the more times the particles hit the walls, the stronger they push on the walls. This results in a force being exerted on each area of wall. Force/unit of area is called pressure. If we squeeze the container into a smaller volume, the particles will not have to travel so far between walls and therefore will hit the walls more frequently, even if the particles are not moving faster. That results in an increase in the pressure on the walls (same force, but smaller area). Part of the evidence for the rapid movement of separate particles of gas is diffusion. For example, the spread of the fragrance of perfume throughout a room.
Particles in a gas move rapidly, are farther apart than in a liquid, and move randomly through the space, colliding with each other and with the boundary walls of the space they occupy. Increasing pressure on a gas-filled container likely decreases the volume containing the gas, if the temperature remains constant. For a fixed volume, if the gas is heated, the average kinetic energy of the particles increases and the gas pressure will increase.
Some changes produce matter with different properties and characteristics from the original matter. During these changes (referred to as "chemical changes"), molecules may break apart, freeing the individual atoms or smaller molecules. These particles collide with one another, and reattach differently from their original attachments. Chemical reactions typically result in an increase or decrease in thermal energy and may happen gradually or result in an explosion.
Some chemical reactions can decompose materials. Substances may be decomposed by acids or bases. Acids and bases can be used to neutralize each other, to make them less capable of decomposing other materials.

Structure of matter

1.7 Understand that all matter is made up of atoms, which may be combined in various kinds, ways, and numbers.

All matter is made of tiny particles (atoms) that cannot be seen without magnification. Atoms do not break down into smaller parts in common day-to-day situations.
Matter made up of one kind of atom is called an element. Only about 100 elements exist. Each element has a unique set of properties. The atoms of those elements can attach to each other in a very large number of ways.
Two or more kinds of elements that react with each other in definite proportions result in matter called a compound. The resulting compound has unique properties that are different from the properties of each of the individual elements it contains. For example, through electrolysis, water can be broken down into hydrogen gas and oxygen gas, always resulting in two units of volume of hydrogen to one unit volume of oxygen.
Two or more atoms attached to each other make up a molecule. A molecule is the smallest particle of an element or compound that can exist by itself and still keep its properties.
A mixture is made up of two or more different kinds of atoms or molecules that keep their original characteristics and can be separated from each other by a simple physical process.
A solution is homogeneous material that does not have a definite chemical composition. It is a mixture wherein one or more substances dissolve in one kind of substance. For example, salt dissolves in water creating a salt water solution. Air is a solution of nitrogen, oxygen, carbon dioxide, water vapor, and many other substances. Solids can even be solutions. The component of a solution that exists in greatest amount is called the solvent. The lessor quantities are called solutes. The greater the amount of solute that dissolves the greater the concentration of the solution. The solution is saturated if no more solute will dissolve. If solute begins to come out of a solution, it is called a precipitate.

Earth Science

Processes and interactions in the earth system

1.1 Correlate global climate to energy transfer by the sun, cloud cover and the earth's rotation, and positions of mountain ranges and oceans.

Weather (in the short run) and climate (in the long run) involve the transfer of energy in and out of the atmosphere. Solar radiation heats the land masses, oceans, and air. Transfer of heat energy at the boundaries between the atmosphere, the land masses, and the ocean results in layers and regions of different temperatures and densities in both the ocean and atmosphere. The action of gravitational force on regions of different density causes them to rise or fall - and such circulation, influenced by the rotation of the earth, produces winds and ocean currents
Global climate is determined by energy transfer from the sun at and near the earth's surface. This energy transfer is influenced by dynamic processes such as cloud cover and the earth's rotation, and static conditions such as the position of mountain ranges and oceans.

Components of the solar system and beyond (universe)

1.2 Describe the relationships of the earth to the sun, the moon, the other planets and their moons, and smaller objects such as asteroids and comets.

The earth is a small planet, third from the sun (a medium-sized star) in one of the few known systems of planets.
The sun is many thousands of times closer to the earth than any other star.
Nine planets of different size, composition, and surface features move around the sun in nearly circular (elliptical) orbits. Some planets have a great variety of moons and flat rings of rock and ice particles orbiting around them.
One moon, many artificial satellites, and debris orbit the earth.
Large numbers of chunks of rock orbit the sun. Some of those that the earth meets in its yearly orbit around the sun glow and disintegrate from friction as they plunge through the atmosphere--and sometime impact the ground. Other chunks or rocks mixed with ice have long, off-center orbits that carry them close to the sun, where the sun's radiation (of light and particles)boils off frozen material from their surfaces and pushes it into a long illuminated tail.

Components and patterns of the earth system: Hydrosphere/atmosphere

1.3 Relate global atmospheric movement and the formation of ocean currents to weather and climate.

The sun is the major source of energy for weather phenomena on the earth's surface, such as winds, ocean currents, and the water cycle.
The cycling of water in and out of the atmosphere plays an important role in determining climatic patterns. Water evaporates from the surface of the earth, rises and cools, condenses into rain or snow, and falls again to the surface. The water falling on land runs off the surface or collects in soil, porous layers of rock, and rivers and lakes, and much of it flows back into the ocean.
Global patterns of atmospheric movement influence local weather. Oceans have a major effect on climate, because water in the oceans holds an enormous amount of thermal energy.
· The sun is the major source of energy for weather phenomena on the earth's surface, such as winds, ocean currents, and the water cycle.
Thermal energy carried by ocean currents has a strong influence on climate around the world, for example El Nino and La Nina.

2. The student conducts scientific investigations.

3. The student understands the nature and contexts of science and technology.

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Blood Drive at Truman		Nov. 21
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Equity Town Hall Meeting		Nov. 22
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