Taken from: http://www.cde.ca.gov/be/st/ss/scgrade8.asp Last modified: Thursday, July 20, 2006



Grade EightScience Content Standards. 



Focus on Physical Science
Motion
 The velocity of an object is the rate of change of its position.
As a basis for understanding this concept:
 Students know position is defined in relation
to some choice of a standard reference point and a set of
reference directions.
 Students know that average speed is the total
distance traveled divided by the total time elapsed and
that the speed of an object along the path traveled can
vary.
 Students know how to solve problems involving
distance, time, and average speed.
 Students know the velocity of an object must
be described by specifying both the direction and the speed
of the object.
 Students know changes in velocity may be due
to changes in speed, direction, or both.
 Students know how to interpret graphs of position
versus time and graphs of speed versus time for motion in
a single direction.
Forces
 Unbalanced forces cause changes in velocity. As a basis for
understanding this concept:
 Students know a force has both direction and
magnitude.
 Students know when an object is subject to two
or more forces at once, the result is the cumulative effect
of all the forces.
 Students know when the forces on an object are
balanced, the motion of the object does not change.
 Students know how to identify separately the
two or more forces that are acting on a single static object,
including gravity, elastic forces due to tension or compression
in matter, and friction.
 Students know that when the forces on an object
are unbalanced, the object will change its velocity (that
is, it will speed up, slow down, or change direction).
 Students know the greater the mass of an object,
the more force is needed to achieve the same rate of change
in motion.
 Students know the role of gravity in forming
and maintaining the shapes of planets, stars, and the solar
system.
Structure of Matter
 Each of the more than 100 elements of matter has distinct
properties and a distinct atomic structure. All forms of matter
are composed of one or more of the elements. As a basis for
understanding this concept:
 Students know the structure of the atom and know
it is composed of protons, neutrons, and electrons.
 Students know that compounds are formed by combining
two or more different elements and that compounds have properties
that are different from their constituent elements.
 Students know atoms and molecules form solids
by building up repeating patterns, such as the crystal structure
of NaCl or longchain polymers.
 Students know the states of matter (solid, liquid,
gas) depend on molecular motion.
 Students know that in solids the atoms are closely
locked in position and can only vibrate; in liquids the
atoms and molecules are more loosely connected and can collide
with and move past one another; and in gases the atoms and
molecules are free to move independently, colliding frequently.
 Students know how to use the periodic table to
identify elements in simple compounds.
Earth in the Solar System (Earth Sciences)
 The structure and composition of the universe can be learned
from studying stars and galaxies and their evolution. As a basis
for understanding this concept:
 Students know galaxies are clusters of billions
of stars and may have different shapes.
 Students know that the Sun is one of many stars
in the Milky Way galaxy and that stars may differ in size,
temperature, and color.
 Students know how to use astronomical units and
light years as measures of distances between the Sun, stars,
and Earth.
 Students know that stars are the source of light
for all bright objects in outer space and that the Moon
and planets shine by reflected sunlight, not by their own
light.
 Students know the appearance, general composition,
relative position and size, and motion of objects in the
solar system, including planets, planetary satellites, comets,
and asteroids.
Reactions
 Chemical reactions are processes in which atoms are rearranged
into different combinations of molecules. As a basis for understanding
this concept:
 Students know reactant atoms and molecules interact
to form products with different chemical properties.
 Students know the idea of atoms explains the
conservation of matter: In chemical reactions the number
of atoms stays the same no matter how they are arranged,
so their total mass stays the same.
 Students know chemical reactions usually liberate
heat or absorb heat.
 Students know physical processes include freezing
and boiling, in which a material changes form with no chemical
reaction.
 Students know how to determine whether a solution
is acidic, basic, or neutral.
Chemistry of Living Systems (Life Sciences)
 Principles of chemistry underlie the functioning of biological
systems. As a basis for understanding this concept:
 Students know that carbon, because of its ability
to combine in many ways with itself and other elements,
has a central role in the chemistry of living organisms.
 Students know that living organisms are made
of molecules consisting largely of carbon, hydrogen, nitrogen,
oxygen, phosphorus, and sulfur.
 Students know that living organisms have many
different kinds of molecules, including small ones, such
as water and salt, and very large ones, such as carbohydrates,
fats, proteins, and DNA.
Periodic Table
 The organization of the periodic table is based on the properties
of the elements and reflects the structure of atoms. As a basis
for understanding this concept:
 Students know how to identify regions corresponding
to metals, nonmetals, and inert gases.
 Students know each element has a specific number
of protons in the nucleus (the atomic number) and each isotope
of the element has a different but specific number of neutrons
in the nucleus.
 Students know substances can be classified by
their properties, including their melting temperature, density,
hardness, and thermal and electrical conductivity.
Density and Buoyancy
 All objects experience a buoyant force when immersed in a
fluid. As a basis for understanding this concept:
 Students know density is mass per unit volume.
 Students know how to calculate the density of
substances (regular and irregular solids and liquids) from
measurements of mass and volume.
 Students know the buoyant force on an object
in a fluid is an upward force equal to the weight of the
fluid the object has displaced.
 Students know how to predict whether an object
will float or sink.
Investigation and Experimentation
 Scientific progress is made by asking meaningful questions
and conducting careful investigations. As a basis for understanding
this concept and addressing the content in the other three strands,
students should develop their own questions and perform investigations.
Students will:
 Plan and conduct a scientific investigation to test a
hypothesis.
 Evaluate the accuracy and reproducibility of data.
 Distinguish between variable and controlled parameters
in a test.
 Recognize the slope of the linear graph as the constant
in the relationship y=kx and apply this principle in interpreting
graphs constructed from data.
 Construct appropriate graphs from data and develop quantitative
statements about the relationships between variables.
 Apply simple mathematic relationships to determine a missing
quantity in a mathematic expression, given the two remaining
terms (including speed = distance/time, density = mass/volume,
force = pressure × area, volume = area × height).
 Distinguish between linear and nonlinear relationships
on a graph of data.





