Motion
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
2. Unbalanced forces cause changes in velocity.
As a basis for
understanding this concept, students know:
a. a 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.
Structure of Matter
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.
Earth in the Solar System (Earth Science)
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.
Reactions
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.
Chemistry of Living Systems (Life Science)
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.
Periodic Table
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.
Density and Buoyancy
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.
Investigation and Experimentation
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.