| EIGHTH GRADE |
SCIENCE (Focus on Physical Science)
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Motion
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Standard
1.
The velocity of
an object is the rate of change of its position. As a basis for understanding
this concept, students know:
a. Position is defined
relative to some choice of standard reference point and a set of reference
directions.
b. Average speed is the total distance traveled
divided by the total time elapsed. The speed of an object along the path
traveled can vary.
c. How to solve problems involving
distance, time, and average speed.
d. To describe the velocity of an object
one must specify both direction and speed.
e. Changes in velocity can be changes
in speed, direction, or both.
f. How to interpret graphs of position versus
time and speed versus time for motion in a single direction.
|
Forces
|
Standard
2.
Unbalanced forces
cause changes in velocity. As a basis for understanding this concept, students
know:
a. S force has both
direction and magnitude.
b. When an object is subject to two or more forces
at once, the effect is the cumulative effect of all the forces.
c. When the forces on an object are balanced,
the motion of the object does not change.
d. How to identify separately two or more forces
acting on a single static object, including gravity, elastic forces due
to tension or compression in matter, and friction.
e. When the forces on an object are unbalanced
the object will change its motion (that is, it will speed up, slow down,
or change direction).
f. The greater the mass of an object the more
force is needed to achieve the same change in motion.
g. The role of gravity in forming and maintaining
planets, stars and the solar system.
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Structure of Matter
|
Standard
3.
Elements
have distinct properties and atomic structure. All matter is comprised
of one or more of over 100 elements. As a basis for understanding this
concept, students know:
a. The structure of
the atom and how it is composed of protons, neutrons and electrons.
b. Compounds are formed by combining two or
more different elements. Compounds have properties that are different from
the constituent elements.
c. Atoms and molecules form solids by building
up repeating patterns such as the crystal structure of NaCl or long chain
polymers.
d. The states (solid, liquid, gas) of matter
depend on molecular motion.
e. 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, while
in gases the atoms or molecules are free to move independently, colliding
frequently.
f. How to use the Periodic Table to identify
elements in simple compounds
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Earth in the Solar System (Earth
Science)
|
Standard
4.
The structure and
composition of the universe can be learned from the study of stars and
galaxies, and their evolution. As a basis for understanding this concept,
students know:
a. Galaxies are clusters
of billions of stars, and may have different shapes.
b. The sun is one of many stars in our own
Milky Way galaxy. Stars may differ in size, temperature, and color.
c. How to use astronomical units and light
years as measures of distance between the sun, stars, and Earth.
d. Stars are the source of light for all bright
objects in outer space. The moon and planets shine by reflected sunlight,
not by their own light.
e. The appearance, general composition, relative
position and size, and motion of objects in the solar system, including
planets, planetary satellites, comets, and asteroids.
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Reactions
|
Standard
5.
Chemical reactions
are processes in which atoms are rearranged into different combinations
of molecules. As a basis for understanding this concept, students know:
a. Reactant atoms
and molecules interact to form products with different chemical properties.
b. 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.
c. Chemical reactions usually liberate heat
or absorb heat.
d. physical processes include freezing and
boiling, in which a material changes form with no chemical reaction.
e. How to determine whether a solution is acidic,
basic or neutral.
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Chemistry of Living Systems
(Life Science)
|
Standard
6.
Principles
of chemistry underlie the functioning of biological systems. As a basis
for understanding this concept, students know:
a. 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.
b. Living organisms are made of molecules largely
consisting of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
c. 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.
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Periodic Table
|
Standard
7.
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:
a. How to identify
regions corresponding to metals, nonmetals and
inert gases.
b. Elements are defined by the number of protons
in the nucleus, which
is called the atomic number. Different isotopes
of an element have a
different number of neutrons in the nucleus.
c. Substances can be classified by their properties,
including melting temperature, density, hardness, heat, and electrical
conductivity.
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Density and Buoyancy
|
Standard
8.
All objects experience
a buoyant force when immersed in a fluid.
As a basis for understanding
this concept, students know:
a. Density is mass
per unit volume.
b. How to calculate the density of
substances (regular and irregular
solids, and liquids) from measurements of
mass and volume.
c. The buoyant force on an object in a fluid
is an upward force equal
to the weight of the fluid it has displaced.
d. How to predict whether an object will float
or sink.
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Investigation and Experimentation
|
Standard
9.
Scientific
progress is made by asking meaningful questions and conducting careful
investigations. As a basis for understanding this concept, and to address
the content the other three strands, students should develop their own
questions and perform investigations. Students will:
a. Plan and conduct
a scientific investigation to test a hypothesis.
b. Evaluate the accuracy and reproducibility
of data.
c. Distinguish between variable and controlled
parameters in a test.
d. Recognize the slope of the linear graph
as the constant in
the relationship y=kx and apply this to interpret
graphs constructed
from data.
e. Construct appropriate graphs from data and
develop quantitative
statements about the relationships between
variables.
f. Apply simple mathematical relationships
to determine one quantity
given the other two (including speed = distance/time,
density = mass/volume, force = pressure x area, volume=area x height).
g. Distinguish between linear and non-linear
relationships on a graph
of data.
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