**Focus on Physical Science**

Grades Nine
Through Twelve

Physics

Science Content Standards

*Standards
that all students are expected to achieve in the course of their studies are
unmarked. Standards that all students should have the opportunity to learn are
colored and marked with an asterisk (*). *

**Motion and Forces **

1. Newton's laws predict the motion of most objects. As a basis for
understanding this concept:

a. *Students know *how to
solve problems that involve constant speed and average speed.

b. *Students know *that when
forces are balanced, no acceleration occurs; thus an object continues to move at
a constant speed or stays at rest (Newton's first law).

c. *Students know *how to
apply the law *F *= *ma *to solve one-dimensional motion problems that
involve constant forces (Newton's second law).

d. *Students know *that when
one object exerts a force on a second object, the second object always exerts a
force of equal magnitude and in the opposite direction (Newton's third law).

e. *Students know *the
relationship between the universal law of gravitation and the effect of gravity
on an object at the surface of Earth.

f. *Students know *applying
a force to an object perpendicular to the direction of its motion causes the
object to change direction but not speed (e.g., Earth's gravitational force
causes a satellite in a circular orbit to change direction but not speed).

g. *Students know *
circular motion requires the application of a constant force directed toward the
center of the circle.

h.* *Students know *Newton's laws are
not exact but provide very good approximations unless an object is moving close
to the speed of light or is small enough that quantum effects are important.

i.* *Students know
*how to solve two-dimensional trajectory problems.

j.* *Students know *how to resolve two-dimensional vectors into their
components and calculate the magnitude and direction of a vector from its
components.

k.* *Students know
*how to solve two-dimensional problems involving balanced forces (statics).

l.* *Students know
*how to solve problems in circular motion by using the formula for
centripetal acceleration in the following form: *a *= *v ^{2}/r*.

m.* *Students know
*how to solve problems involving the forces between two electric charges at a
distance (Coulomb's law) or the forces between two masses at a distance
(universal gravitation).

**Conservation of Energy and
Momentum **

2. The laws of conservation of energy and momentum provide a way to predict and
describe the movement of objects. As a basis for understanding this concept:

a. *Students know *how to
calculate kinetic energy by using the formula *E *= *(1/2)mv ^{2}*.

b.

c. *Students know *how to
solve problems involving conservation of energy in simple systems, such as
falling objects.

d. *Students know *how to
calculate momentum as the product *mv. *

e. *Students know *momentum is a separately conserved quantity different
from energy.

f. *Students know *an
unbalanced force on an object produces a change in its momentum.

g. *Students know *how to
solve problems involving elastic and inelastic collisions in one dimension by
using the principles of conservation of momentum and energy.

h.* *Students know
*how to solve problems involving conservation of energy in simple systems
with various sources of potential energy, such as capacitors and springs.

**Heat and Thermodynamics **

3. Energy cannot be created or destroyed, although in many processes energy is
transferred to the environment as heat. As a basis for understanding this
concept:

a. *Students know *heat flow
and work are two forms of energy transfer between systems.

b. *Students know *that the
work done by a heat engine that is working in a cycle is the difference between
the heat flow into the engine at high temperature and the heat flow out at a
lower temperature (first law of thermodynamics) and that this is an example of
the law of conservation of energy.

c. *Students know *the
internal energy of an object includes the energy of random motion of the
object's atoms and molecules, often referred to as *thermal energy. *The
greater the temperature of the object, the greater the energy of motion of the
atoms and molecules that make up the object.

d. *Students know *that most
processes tend to decrease the order of a system over time and that energy
levels are eventually distributed uniformly.

e. *Students know *that
entropy is a quantity that measures the order or disorder of a system and that
this quantity is larger for a more disordered system.

f.* *Students know
*the statement "Entropy tends to increase" is a law of statistical
probability that governs all closed systems (second law of thermodynamics).

g.* *Students know
*how to solve problems involving heat flow, work, and efficiency in a heat
engine and know that all real engines lose some heat to their surroundings.

**Waves **

4. Waves have characteristic properties that do not depend on the type of wave.
As a basis for understanding this concept:

a. *Students know *waves
carry energy from one place to another.

b. *Students know *how to identify transverse and longitudinal waves in
mechanical media, such as springs and ropes, and on the earth (seismic waves).

c. *Students know *how to
solve problems involving wavelength, frequency, and wave speed.

d. *Students know *sound is
a longitudinal wave whose speed depends on the properties of the medium in which
it propagates.

e. *Students know *radio
waves, light, and X-rays are different wavelength bands in the spectrum of
electromagnetic waves whose speed in a vacuum is approximately 3 x 10^{8}m/s
(186,000 miles/second).

f. *Students know *how to
identify the characteristic properties of waves: interference (beats),
diffraction, refraction, Doppler effect, and polarization.

**Electric and Magnetic
Phenomena **

5. Electric and magnetic phenomena are related and have many practical
applications. As a basis for understanding this concept:

a. *Students know *how to
predict the voltage or current in simple direct current (DC) electric circuits
constructed from batteries, wires, resistors, and capacitors.

b. *Students know *how to
solve problems involving Ohm's law.

c. *Students know *any resistive element in a DC circuit dissipates energy,
which heats the resistor. Students can calculate the power (rate of energy
dissipation) in any resistive circuit element by using the formula Power = *IR
*(potential difference) x *I *(current) = *1 ^{2}R*.

d. *Students know *the
properties of transistors and the role of transistors in electric circuits.

e. *Students know *charged
particles are sources of electric fields and are subject to the forces of the
electric fields from other charges.

f. *Students know *magnetic
materials and electric currents (moving electric charges) are sources of
magnetic fields and are subject to forces arising from the magnetic fields of
other sources.

g. *Students know *how to
determine the direction of a magnetic field produced by a current flowing in a
straight wire or in a coil.

h. *Students know *changing
magnetic fields produce electric fields, thereby inducing currents in nearby
conductors.

i. *Students know *plasmas,
the fourth state of matter, contain ions or free electrons or both and conduct
electricity.

j.* *Students know
*electric and magnetic fields contain energy and act as vector force fields.

k.* *Students know
*the force on a charged particle in an electric field is *qE, *where *
E* is the electric field at the position of the particle and *q *is the
charge of the particle.

l.* *Students know *how to calculate the electric field resulting from a
point charge.

m.* *Students know *static electric fields have as their source some
arrangement of electric charges.

n.* *Students know
*the magnitude of the force on a moving particle (with charge *q) *in a
magnetic field is *qvB *sin(*a), *where *a *is the angle between
*v *and *B *(v and *B *are the magnitudes of vectors *v *and
*B, *respectively), and students use the right-hand rule to find the
direction of this force.

o.* *Students know
*how to apply the concepts of electrical and gravitational potential energy
to solve problems involving conservation of energy.

Grades Nine
Through Twelve

Chemistry

Science Content Standards

Curriculum > Standards > Science > Chemistry

*Standards
that all students are expected to achieve in the course of their studies are
unmarked. Standards that all students should have the opportunity to learn are
colored and marked with an asterisk (*). *

**Atomic and Molecular Structure
**

1. The periodic table displays the elements in increasing atomic number and
shows how periodicity of the physical and chemical properties of the elements
relates to atomic structure. As a basis for understanding this concept:

a. *Students know *how to
relate the position of an element in the periodic table to its atomic number and
atomic mass.

b. *Students know *how to
use the periodic table to identify metals, semimetals, non-metals, and halogens.

c. *Students know *how to
use the periodic table to identify alkali metals, alkaline earth metals and
transition metals, trends in ionization energy, electro negativity, and the
relative sizes of ions and atoms.

d. *Students know *how to
use the periodic table to determine the number of electrons available for
bonding.

e. *Students know *the
nucleus of the atom is much smaller than the atom yet contains most of its mass.

f.* *Students know
*how to use the periodic table to identify the lanthanide, actinide, and
transactinide elements and know that the transuranium elements were synthesized
and identified in laboratory experiments through the use of nuclear
accelerators.

g.* *Students know
*how to relate the position of an element in the periodic table to its
quantum electron configuration and to its reactivity with other elements in the
table.

h.* *Students know
*the experimental basis for Thomson's discovery of the electron, Rutherford's
nuclear atom, Millikan's oil drop experiment, and Einstein's explanation of the
photoelectric effect.

i.* *Students know
*the experimental basis for the development of the quantum theory of atomic
structure and the historical importance of the Bohr model of the atom.

j.* *Students know
*that spectral lines are the result of transitions of electrons between
energy levels and that these lines correspond to photons with a frequency
related to the energy spacing between levels by using Planck's relationship (E =
*hv). *

**Chemical Bonds **

2. Biological, chemical, and physical properties of matter result from the
ability of atoms to form bonds from electrostatic forces between electrons and
protons and between atoms and molecules. As a basis for understanding this
concept:

a. *Students know *atoms
combine to form molecules by sharing electrons to form covalent or metallic
bonds or by exchanging electrons to form ionic bonds.

b. *Students know *chemical
bonds between atoms in molecules such as H_{2}, CH_{4}, NH_{3},
H_{2}CCH_{2}, N_{2}, Cl_{2}, and many large
biological molecules are covalent.

c. *Students know *salt
crystals, such as NaCl, are repeating patterns of positive and negative ions
held together by electrostatic attraction.

d. *Students know *the atoms
and molecules in liquids move in a random pattern relative to one another
because the intermolecular forces are too weak to hold the atoms or molecules in
a solid form.

e. *Students know *how
to draw Lewis dot structures.

f.* *Students know *how to predict the
shape of simple molecules and their polarity from Lewis dot structures.

g.* *Students know
*how electronegativity and ionization energy relate to bond formation.

h.* *Students know
*how to identify solids and liquids held together by Van der Waals forces or
hydrogen bonding and relate these forces to volatility and boiling/melting point
temperatures.

**Conservation of Matter and
Stoichiometry **

3. The conservation of atoms in chemical reactions leads to the principle of
conservation of matter and the ability to calculate the mass of products and
reactants. As a basis for understanding this concept:

a. *Students know *how to
describe chemical reactions by writing balanced equations.

b. *Students know *the quantity *one mole *is set by defining one mole
of carbon 12 atoms to have a mass of exactly 12 grams.

c. *Students know *one mole
equals 6.02 x 10^{23} particles (atoms or molecules).

d. *Students know *how to determine the molar mass of a molecule from its
chemical formula and a table of atomic masses and how to convert the mass of a
molecular substance to moles, number of particles, or volume of gas at standard
temperature and pressure.

e. *Students know *how to calculate the masses of reactants and products in
a chemical reaction from the mass of one of the reactants or products and the
relevant atomic masses.

f.* *Students know
*how to calculate percent yield in a chemical reaction.

g.* *Students know *how to identify reactions that involve oxidation and
reduction and how to balance oxidation-reduction reactions.

**Gases and Their Properties **

4. The kinetic molecular theory describes the motion of atoms and molecules and
explains the properties of gases. As a basis for understanding this concept:

a. *Students know *the
random motion of molecules and their collisions with a surface create the
observable pressure on that surface.

b. *Students know *the
random motion of molecules explains the diffusion of gases.

c. *Students know *how to apply the gas laws to relations between the
pressure, temperature, and volume of any amount of an ideal gas or any mixture
of ideal gases.

d. *Students know *the
values and meanings of standard temperature and pressure (STP).

e. *Students know *how
to convert between the Celsius and Kelvin temperature scales.

f. *Students know *there is no temperature lower than 0 Kelvin.

g.* *Students know *the kinetic theory
of gases relates the absolute temperature of a gas to the average kinetic energy
of its molecules or atoms.

h.* *Students know
*how to solve problems by using the ideal gas law in the form *PV *= *
nRT. *

i.* *Students know
*how to apply Dalton's law of partial pressures to describe the composition
of gases and Graham's law to predict diffusion of gases.

**Acids and Bases **

5. Acids, bases, and salts are three classes of compounds that form ions in
water solutions. As a basis for understanding this concept:

a. *Students know *the
observable properties of acids, bases, and salt solutions.

b. *Students know *acids are hydrogen-ion-donating and bases are
hydrogen-ion-accepting substances.

c. *Students know *strong
acids and bases fully dissociate and weak acids and bases partially dissociate.

d. *Students know *how
to use the pH scale to characterize acid and base solutions.

e.* *Students know *the Arrhenius,
Bronsted-Lowry, and Lewis acid-base definitions.

f.* *Students know *how to calculate pH from the hydrogen-ion
concentration.

g.* *Students know *buffers stabilize pH in acid-base reactions.

**Solutions **

6. Solutions are homogenous mixtures of two or more substances. As a basis for
understanding this concept:

a. *Students know *the
definitions of *solute *and *solvent.
*b.

c. *Students know *
temperature, pressure, and surface area affect the dissolving process.

d. *Students know *how to
calculate the concentration of a solute in terms of grams per liter, molarity,
parts per million, and percent composition.

e.* *Students know
*the relationship between the molality of a solute in a solution and the
solution's depressed freezing point or elevated boiling point.

f.* *Students know
*how molecules in a solution are separated or purified by the methods of
chromatography and distillation.

**Chemical Thermodynamics **

7. Energy is exchanged or transformed in all chemical reactions and physical
changes of matter. As a basis for understanding this concept:

a. *Students know *how to
describe temperature and heat flow in terms of the motion of molecules (or
atoms).

b. *Students know *chemical
processes can either release (exothermic) or absorb (endothermic) thermal
energy.

c. *Students know *energy is
released when a material condenses or freezes and is absorbed when a material
evaporates or melts.

d. *Students know *how to
solve problems involving heat flow and temperature changes, using known values
of specific heat and latent heat of phase change.

e.* *Students know
*how to apply Hess's law to calculate enthalpy change in a reaction.

f.* *Students know *how to use the Gibbs free energy equation to determine
whether a reaction would be spontaneous.

**Reaction Rates **

8. Chemical reaction rates depend on factors that influence the frequency of
collision of reactant molecules. As a basis for understanding this concept:

a. *Students know *the rate
of reaction is the decrease in concentration of reactants or the increase in
concentration of products with time.

b. *Students know *how
reaction rates depend on such factors as concentration, temperature, and
pressure.

c. *Students know *the
role a catalyst plays in increasing the reaction rate.

d.* *Students know *the definition and
role of activation energy in a chemical reaction.

**Chemical Equilibrium **

9. Chemical equilibrium is a dynamic process at the molecular level. As a basis
for understanding this concept:

a. *Students know *how to
use LeChatelier's principle to predict the effect of changes in concentration,
temperature, and pressure.

b. *Students know *
equilibrium is established when forward and reverse reaction rates are equal.

c.* *Students know
*how to write and calculate an equilibrium constant expression for a
reaction.

**Organic Chemistry and
Biochemistry **

10. The bonding characteristics of carbon allow the formation of many different
organic molecules of varied sizes, shapes, and chemical properties and provide
the biochemical basis of life. As a basis for understanding this concept:

a. *Students know *large
molecules (polymers), such as proteins, nucleic acids, and starch, are formed by
repetitive combinations of simple subunits.

b. *Students know *the
bonding characteristics of carbon that result in the formation of a large
variety of structures ranging from simple hydrocarbons to complex polymers and
biological molecules.

c. *Students know *amino
acids are the building blocks of proteins.

d.* *Students know
*the system for naming the ten simplest linear hydrocarbons and isomers that
contain single bonds, simple hydrocarbons with double and triple bonds, and
simple molecules that contain a benzene ring.

e.* *Students know
*how to identify the functional groups that form the basis of alcohols,
ketones, ethers, amines, esters, aldehydes, and organic acids.

f.* *Students know
*the R-group structure of amino acids and know how they combine to form the
polypeptide backbone structure of proteins.

**Nuclear Processes **

11. Nuclear processes are those in which an atomic nucleus changes, including
radioactive decay of naturally occurring and human-made isotopes, nuclear
fission, and nuclear fusion. As a basis for understanding this concept:

a. *Students know *protons
and neutrons in the nucleus are held together by nuclear forces that overcome
the electromagnetic repulsion between the protons.

b. *Students know *the
energy release per gram of material is much larger in nuclear fusion or fission
reactions than in chemical reactions. The change in mass (calculated by *E *
= *mc ^{2}*) is small but significant in nuclear reactions.

c. *Students know *some
naturally occurring isotopes of elements are radioactive, as are isotopes formed
in nuclear reactions.

d. *Students know *the three
most common forms of radioactive decay (alpha, beta, and gamma) and know how the
nucleus changes in each type of decay.

e. *Students know *alpha,
beta, and gamma radiation produce different amounts and kinds of damage in
matter and have different penetrations.

f.* *Students know
*how to calculate the amount of a radioactive substance remaining after an
integral number of half lives have passed.

g.* *Students know
*protons and neutrons have substructures and consist of particles called
quarks.

Grades Nine
Through Twelve

Earth Sciences

Science Content Standards

Curriculum > Standards > Science > Earth Sciences

*Standards
that all students are expected to achieve in the course of their studies are
unmarked. Standards that all students should have the opportunity to learn are
colored and marked with an asterisk (*). *

**Earth's Place in the Universe
**

1. Astronomy and planetary exploration reveal the solar system's structure,
scale, and change over time. As a basis for understanding this concept:

a. *Students know *how the
differences and similarities among the sun, the terrestrial planets, and the gas
planets may have been established during the formation of the solar system.

b. *Students know *the
evidence from Earth and moon rocks indicates that the solar system was formed
from a nebular cloud of dust and gas approximately 4.6 billion years ago.

c. *Students know *the
evidence from geological studies of Earth and other planets suggest that the
early Earth was very different from Earth today.

d. *Students know *the
evidence indicating that the planets are much closer to Earth than the stars
are.

e. *Students know *the Sun
is a typical star and is powered by nuclear reactions, primarily the fusion of
hydrogen to form helium.

f. *Students know *the
evidence for the dramatic effects that asteroid impacts have had in shaping the
surface of planets and their moons and in mass extinctions of life on Earth.

g.* *Students know
*the evidence for the existence of planets orbiting other stars.

2. Earth-based and space-based astronomy reveal the structure, scale, and changes in stars, galaxies, and the universe over time. As a basis for understanding this concept:

a. *Students know *the solar
system is located in an outer edge of the disc-shaped Milky Way galaxy, which
spans 100,000 light years.

b. *Students know *galaxies
are made of billions of stars and comprise most of the visible mass of the
universe.

c. *Students know *the
evidence indicating that all elements with an atomic number greater than that of
lithium have been formed by nuclear fusion in stars.

d. *Students know *that
stars differ in their life cycles and that visual, radio, and X-ray telescopes
may be used to collect data that reveal those differences.

e.* *Students know
*accelerators boost subatomic particles to energy levels that simulate
conditions in the stars and in the early history of the universe before stars
formed.

f.* *Students know *the evidence indicating that the color, brightness, and
evolution of a star are determined by a balance between gravitational collapse
and nuclear fusion.

g.* *Students know
*how the red-shift from distant galaxies and the cosmic background radiation
provide evidence for the "big bang" model that suggests that the universe has
been expanding for 10 to 20 billion years.

**Dynamic Earth Processes **

3. Plate tectonics operating over geologic time has changed the patterns of
land, sea, and mountains on Earth's surface. As the basis for understanding this
concept:

a. *Students know *features
of the ocean floor (magnetic patterns, age, and sea-floor topography) provide
evidence of plate tectonics.

b. *Students know *the
principal structures that form at the three different kinds of plate boundaries.

c. *Students know *how to
explain the properties of rocks based on the physical and chemical conditions in
which they formed, including plate tectonic processes.

d. *Students know *why and
how earthquakes occur and the scales used to measure their intensity and
magnitude.

e. *Students know *there are
two kinds of volcanoes: one kind with violent eruptions producing steep slopes
and the other kind with voluminous lava flows producing gentle slopes.

f.* *Students know
*the explanation for the location and properties of volcanoes that are due to
hot spots and the explanation for those that are due to subduction.

**Energy in the Earth System **

4. Energy enters the Earth system primarily as solar radiation and eventually
escapes as heat. As a basis for understanding this concept:

a. *Students know *the
relative amount of incoming solar energy compared with Earth's internal energy
and the energy used by society.

b. *Students know *the fate
of incoming solar radiation in terms of reflection, absorption, and
photosynthesis.

c. *Students know *the
different atmospheric gases that absorb the Earth's thermal radiation and the
mechanism and significance of the greenhouse effect.

d.* *Students know
*the differing greenhouse conditions on Earth, Mars, and Venus; the origins
of those conditions; and the climatic consequences of each.

5. Heating of Earth's surface and atmosphere by the sun drives convection within the atmosphere and oceans, producing winds and ocean currents. As a basis for understanding this concept:

a. *Students know *how
differential heating of Earth results in circulation patterns in the atmosphere
and oceans that globally distribute the heat.

b. *Students know *the
relationship between the rotation of Earth and the circular motions of ocean
currents and air in pressure centers.

c. *Students know *the
origin and effects of temperature inversions.

d. *Students know *properties of ocean water, such as temperature and
salinity, can be used to explain the layered structure of the oceans, the
generation of horizontal and vertical ocean currents, and the geographic
distribution of marine organisms.

e. *Students know *rain
forests and deserts on Earth are distributed in bands at specific latitudes.

f.* *Students know
*the interaction of wind patterns, ocean currents, and mountain ranges
results in the global pattern of latitudinal bands of rain forests and deserts.

g.* *Students know
*features of the ENSO (El Niņo southern oscillation) cycle in terms of
sea-surface and air temperature variations across the Pacific and some climatic
results of this cycle.

6. Climate is the long-term average of a region's weather and depends on many factors. As a basis for understanding this concept:

a. *Students know *weather
(in the short run) and climate (in the long run) involve the transfer of energy
into and out of the atmosphere.

b. *Students know *the
effects on climate of latitude, elevation, topography, and proximity to large
bodies of water and cold or warm ocean currents.

c. *Students know *how
Earth's climate has changed over time, corresponding to changes in Earth's
geography, atmospheric composition, and other factors, such as solar radiation
and plate movement.

d.* *Students know
*how computer models are used to predict the effects of the increase in
greenhouse gases on climate for the planet as a whole and for specific regions.

**Biogeochemical Cycles **

7. Each element on Earth moves among reservoirs, which exist in the solid earth,
in oceans, in the atmosphere, and within and among organisms as part of
biogeochemical cycles. As a basis for understanding this concept:

a. *Students know *the
carbon cycle of photosynthesis and respiration and the nitrogen cycle.

b. *Students know *the
global carbon cycle: the different physical and chemical forms of carbon in the
atmosphere, oceans, biomass, fossil fuels, and the movement of carbon among
these reservoirs.

c. *Students know *the
movement of matter among reservoirs is driven by Earth's internal and external
sources of energy.

d.* *Students know
*the relative residence times and flow characteristics of carbon in and out
of its different reservoirs.

**Structure and Composition of
the Atmosphere **

8. Life has changed Earth's atmosphere, and changes in the atmosphere affect
conditions for life. As a basis for understanding this concept:

a. *Students know *the
thermal structure and chemical composition of the atmosphere.

b. *Students know *how the composition of Earth's atmosphere has evolved
over geologic time and know the effect of outgassing, the variations of carbon
dioxide concentration, and the origin of atmospheric oxygen.

c. *Students know *the
location of the ozone layer in the upper atmosphere, its role in absorbing
ultraviolet radiation, and the way in which this layer varies both naturally and
in response to human activities.

**California Geology **

9. The geology of California underlies the state's wealth of natural resources
as well as its natural hazards. As a basis for understanding this concept:

a. *Students know *the
resources of major economic importance in California and their relation to
California's geology.

b. *Students know *the
principal natural hazards in different California regions and the geologic basis
of those hazards.

c. *Students know *the
importance of water to society, the origins of California's fresh water, and the
relationship between supply and need.

d.* *Students know
*how to analyze published geologic hazard maps of California and know how to
use the map's information to identify evidence of geologic events of the past
and predict geologic changes in the future.

Grades Nine
Through Twelve

Investigation and Experimentation

Science Content Standards

Curriculum > Standards > Science > Investigation

1. 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 four strands, students should develop their own questions and perform investigations. Students will:

a. Select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data.

b. Identify and communicate
sources of unavoidable experimental error.

c. Identify possible reasons for inconsistent results, such as sources of error
or uncontrolled conditions.

d. Formulate explanations by
using logic and evidence.

e. Solve scientific problems by using quadratic equations and simple
trigonometric, exponential, and logarithmic functions.

f. Distinguish between hypothesis
and theory as scientific terms.

g. Recognize the usefulness and limitations of models and theories as scientific
representations of reality.

h. Read and interpret topographic
and geologic maps.

i. Analyze the locations, sequences, or time intervals that are characteristic
of natural phenomena (e.g., relative ages of rocks, locations of planets over
time, and succession of species in an ecosystem).

j. Recognize the issues of
statistical variability and the need for controlled tests.

k. Recognize the cumulative nature of scientific evidence.

l. Analyze situations and solve problems that require combining and applying
concepts from more than one area of science.

m. Investigate a science-based societal issue by researching the literature, analyzing data, and communicating the findings. Examples of issues include irradiation of food, cloning of animals by somatic cell nuclear transfer, choice of energy sources, and land and water use decisions in California.

n. Know that when an observation does not agree with an accepted scientific theory, the observation is sometimes mistaken or fraudulent (e. g., the Piltdown Man fossil or unidentified flying objects) and that the theory is sometimes wrong (e.g., the Ptolemaic model of the movement of the Sun, Moon, and planets).