8TH
GRADE
The
Nature of Science and Technology
Students
design and carry out increasingly sophisticated investigations. They understand
the reason for isolating and controlling variables in an investigation. They
realize that scientific knowledge is subject to change as new evidence arises.
They examine issues in the design and use of technology, including constraints,
safeguards, and trade-offs.
Recognize
that and describe how scientific knowledge is subject to modification as new
information challenges prevailing theories and as a new theory leads to looking
at old observations in a new way. (Core Standard)
Recognize
and explain that some matters cannot be examined usefully in a scientific way.
Recognize
and describe that if more than one variable changes at the same time in an
experiment, the outcome of the experiment may not be attributable to any one of
the variables. (Core Standard)
Explain
why accurate record keeping, openness, and replication are essential for
maintaining an investigator's credibility with other scientists and society.
Explain
why research involving human subjects requires potential subjects be fully
informed about the risks and benefits associated with the research and that they
have the right to refuse to participate.
Identify
the constraints that must be taken into account as a new design is developed,
such as gravity and the properties of the materials to be used. (Core
Standard)
Explain
why technology issues are rarely simple and one-sided because contending groups
may have different values and priorities. (Core
Standard)
Explain
that humans help shape the future by generating knowledge, developing new
technologies, and communicating ideas to others. (Core
Standard)
Scientific
Thinking
Students
use computers to organize and compare information. They perform calculations and
determine the appropriate units for the answers.
They weigh the evidence for or against an argument, as well as the logic
of the conclusions.
Estimate
distances and travel times from maps and the actual size of objects from scale
drawings.
Determine
in what unit, such as seconds, meters, grams, etc., an answer should be
expressed based on the units of the inputs to the calculation
Use
proportional reasoning to solve problems.
Use
technological devices, such as calculators and computers, to perform
calculations.
Use
computers to store and retrieve information in topical, alphabetical, numerical,
and keyword files and create simple files of students' own devising.
Write
clear, step-by-step instructions (procedural summaries) for conducting
investigations, operating something, or following a procedure.
Participate
in group discussions on scientific topics by restating or summarizing accurately
what others have said, asking for clarification or elaboration, and expressing
alternative positions. (Core Standard)
Use
tables, charts, and graphs in making arguments and claims in, for example, oral
and written presentations about lab or fieldwork. (Core
Standard)
Explain
why arguments are invalid if based on very small samples of data, biased
samples, or samples for which there was no control sample.
Identify
and criticize the reasoning in arguments in which fact and opinion are
intermingled or the conclusions do not follow logically from the evidence given,
an analogy is not apt, no mention is made of whether the control group is very
much like the experimental group, or all members of a group are implied to have
nearly identical characteristics that differ from those of other groups.
The
Physical Setting
Students
collect and organize data to identify relationships between physical objects,
events, and processes. They use logical reasoning to question their own ideas as
new information challenges their conceptions of the natural world.
Explain
that large numbers of chunks of rock orbit the sun and some of this rock
interacts with the Earth.
Explain
that the slow movement of material within the Earth results from heat flowing
out of the deep interior and the action of gravitational forces on regions of
different density. (Core Standard)
Explain
that the solid crust of Earth, including both the continents and the ocean
basins, consists of separate plates that ride on a denser, hot, gradually
deformable layer of earth. Understand that the crust sections move very slowly,
pressing against one another in some places, pulling
Explain
that earthquakes often occur along the boundaries between colliding plates, and
molten rock from below creates pressure that is released by volcanic eruptions,
helping to build up mountains. Understand that under the ocean basins, molten
rock may well up between separating plates to create new ocean floor. Further
understand that volcanic activity along the ocean floor may form undersea
mountains, which can thrust above the ocean's surface to become islands. (Core
Standard)
Explain
that everything on or anywhere near the Earth is pulled toward the Earth's
center by a gravitational force. (Core Standard)
Understand
and explain that the benefits of the Earth's resources, such as fresh water,
air, soil, and trees, are finite and can be reduced by using them wastefully or
by deliberately or accidentally destroying them.
Explain
that the atmosphere and the oceans have a limited capacity to absorb wastes and
recycle materials naturally.
Explain
that all matter is made up of atoms which are far too small to see directly
through an optical microscope. Understand that the atoms of any element are
similar but are different from atoms of other elements. Further understand that
atoms may stick together in well-definedmolecules or may be packed together in
large arrays. Also understand that different arrangements of atoms into groups
comprise all substances.
(Core Standard)
Demonstrate,
using drawings and models, the movement of atoms in a solid, liquid, and gaseous
state. Explain that atoms and molecules are perpetually in motion. (Core
Standard)
Explain
that increased temperature means that atoms have a greater average energy of
motion and that most gases expand when heated. (Core
Standard)
The
Living Environment
Students
trace the flow of matter and energy through ecosystems. They understand that the
total amount of matter remians constant and that almost all food energy has its
origin in sunlight.
Differentiate
between inherited traits, such as hair color or flower color, and acquired
skills, such as manners. (Core Standard)
Describe
that in some organisms, such as yeast or bacteria, all genes come from a single
parent, while in those that have sexes, typically half of the genes come from
each parent. (Core Standard)
Recognize
and describe that new varieties of cultivated plants, such as corn and apples,
and domestic animals, such as dogs and horses, have resulted from selective
breeding for particular traits. (Core Standard)
Describe
how matter is transferred from one organism to another repeatedly and between
organisms and their physical environment.
Explain
that energy can be transferred from one form to another in living things.
Describe
how animals get their energy from oxidizing their food and releasing some of
this energy as heat.
Recognize
and explain that small genetic differences between parents and offspring can
accumulate in successive generations so that descendents are very different from
their ancestors.
Describe
how environmental conditions affect the survival of individual organisms and how
entire species may prosper in spite of the poor survivability or bad fortune of
individuals.
Recognize
and describe that fossil evidence is consistent with the idea that human beings
evolved from earlier species. (Core Standard)
The
Mathematical World
Students
apply mathematics in scientific contexts. Students use mathematical ideas, such
as symbols, geometrical relationships, and the use of keywords and rules in
logical reasoning, in the representation and synthesis of data.
Understand
and explain that a number must be written with an appropriate number of
significant figures. (determined by the measurements from which the number is
derived).
Show
that an equation containing a variable may be true for just one value of the
variable.
Demonstrate
that mathematical statements can be used to describe how one quantity changes
when another changes.
Illustrate
how graphs can show a variety of possible relationships between two variables.
Illustrate
that it takes two numbers to locate a point on a map or any other
two-dimensional surface.
Explain
that a single example can never prove that something is always true, but it
could prove that something is not always true. (Core
Standard)
Recognize
and describe the danger of making over-generalizations when inventing a general
rule based on a few observations.
Explain
how estimates can be based on data from similar conditions in the past or on the
assumption that all the possibilities are known.
Compare
the mean, median, and mode of a data set.
Explain
how the comparison of data from two groups involves comparing both their middles
and the spreads.
Historical
Perspectives
Students
gain understanding of how the scientific enterprise operates through examples of
historical events. Through the study of these events, they
Understand
and explain that Antoine Lavoisier's work was based on the idea that when
materials react with each other, many changes can take
Understand
and describe that the accidental discovery that minerals containing uranium
darken photographic film, as light does, led to the discovery of radioactivity.
Understand
that and describe how in their laboratory in France, Marie Curie and her
husband, Pierre Curie, isolated two new elements that were the source of most of
the radioactivity of uranium ore. Note that they named one radium because it
gave off powerful invisible rays, and the other polonium in honor of Madame
Curie's country of birth, Poland. Also note that Marie Curie was the first
scientist ever to win the Nobel Prize in two different fields, in physics,
shared with her husband, and later in chemistry.
Describe
how the discovery of radioactivity as a source of the Earth's heat energy made
it possible to understand how the Earth can be several billion years old and
still have a hot interior.
Common
Themes
Students
analyze the parts and interactions of systems to understand internal and
external relationships. They investigate rates of change, cyclic changes, and
changes that counterbalance one another. They use mental and physical models to
reflect upon and interpret the limitations of such models.
Explain
that a system usually has some properties that are different from those of its
parts but appear because of the interaction of those parts.
Explain
that even in some very simple systems, it may not always be possible to predict
accurately the result of changing some part or connection.
Use
technology to assist in graphing and with simulations that compute and display
results of changing factors in models.
Explain
that as the complexity of any system increases, gaining an understanding of it
depends on summaries, such as averages and ranges, and on descriptions of
typical examples of that system.
Observe
and describe that a system may stay the same because nothing is happening or
because things are happening that counteract one another.
Recognize
that and describe how symmetry may determine properties of many objects, such as
molecules, crystals, organisms, and designed structures.
Illustrate
how things, such as seasons or body temperature, occur in cycles.