PA Benchmarks: Science
Draft: January 30, 2007
EARTH & SPACE SCIENCE
1
LIFE SCIENCE
1. The Chemistry of Life
Central Concept: Chemical elements form organic molecules that interact to
perform the basic functions of life.
1.1
1.2
1.3
1.4
Recognize that biological organisms are composed primarily of very few
elements. The six most common are C, H, N, O, P, and S.
Describe the basic molecular structures and primary functions of the four
major categories of organic molecules in plants and animals
(carbohydrates, lipids, proteins, nucleic acids, ATP).
Explain the role of enzymes as catalysts that lower the activation energy
of biochemical reactions.
Life has a very narrow range of acceptable conditions in which to
flourish. Identify factors, such as pH and temperature, which have an
effect on biochemical reactions.
2. Cell Biology
Central Concepts: Cells have specific structures and functions that make them
distinctive. Processes in a cell can be classified broadly as growth, maintenance,
and reproduction.
2.1
2.2
2.3
2.4
2.5
Relate cell parts/organelles (plasma membrane, nuclear envelope,
nucleus, nucleolus, cytoplasm, mitochondrion, endoplasmic reticulum,
Golgi apparatus, lysosome, ribosome, vacuole, cell wall, chloroplast,
cytoskeleton, centriole, cilium, flagellum, pseudopod) to their functions.
Explain the role of cell membranes as a highly selective barrier
cytoplasm and the environment. Processes that allow transport across
this barrier include diffusion, osmosis, facilitated diffusion, active
transport.
Compare and contrast, at the cellular level, the cell parts/organelles of
prokaryotes and eukaryotes.
Use cellular evidence (e.g., cell structure, cell number, cell reproduction)
and modes of nutrition to describe the known kingdoms i.e.;
Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia.
Identify the reactants, products, and basic purposes of photosynthesis
and cellular respiration. Explain the interrelated nature of photosynthesis
and cellular respiration in the cells of photosynthetic organisms.
Identify the reactants, products and metabolic cycles that generate ATP.
Identify the important role that ATP serves in cell metabolism.
Demonstrate the network of pathways that interact with the ATP
metabolic cycle or any other reaction utilizing online bioinformatics tools
such as the ExPASy Biochemical Pathways (http://www.expasy.ch/cgibin/search-biochem-index) or the KEGG Pathway
(http://www.genome.jp/kegg/pathway.html)
2
2.6
2.7
2.8
Describe cell replication and the process of mitosis. Explain the role of
mitosis in the formation of new cells, and its importance in maintaining
chromosome number during asexual reproduction.
Describe how the process of meiosis results in the formation of haploid
cells. Explain the importance of this process in sexual reproduction, and
how gametes form diploid zygotes in the process of fertilization.
Compare and contrast a virus and a cell in terms of structure and
function.
3. Genetics and Molecular Biology
Central Concepts: Genes allow for the storage and transmission of genetic
information. They are a set of instructions encoded in the nucleotide sequence of
each organism. Genes code for the specific sequences of amino acids that
comprise proteins.
3.1
3.2
3.3
3.4
3.5
3.6
Describe the basic structure (double helix, sugar/phosphate backbone,
linked by complementary nucleotide pairs) of DNA
Describe the basic process of DNA replication and how it relates to the
transmission and conservation of the genetic code. Explain the basic
processes of transcription and translation, and how they result in the
expression of genes. Distinguish among the end products of replication,
transcription, and translation.
Explain how variation (as in the DNA sequence of a gene may or may
not (positive, neutral or negative) result in phenotypic change in an
organism. Naturally occurring variations are rare and random. Discuss
the environmental factors that increase the frequency of mutation
(tetrogenic; UV, chemical, viral). Explore the significance of conservative
and non-conservative sequences within the genome of an organism
using online public bioinformatics tools such as UCSC’s Genome
Browser (http://genome.ucsc.edu/cgi-bin/hgGateway) or NCBI OMIM
(http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMIM)
Distinguish among observed inheritance patterns caused by several
types of genetic traits (dominant, recessive, codominant, sex-linked,
polygenic, incomplete dominance, multiple alleles).
Describe how Mendel’s laws of segregation and independent assortment
can be observed through patterns of inheritance (e.g., dihybrid crosses).
Use a Punnett Square to determine the mathematical probabilities for
genotype and phenotype combinations in monohybrid crosses.
4. Mammalian Anatomy and Physiology
Central Concepts: There is a relationship between the organization of cells into
tissues and the organization of tissues into organs. The structures and functions
of organs determine their relationships within body systems of an organism.
Homeostasis allows the body to perform its normal functions.
3
4.1
Explain how the digestive system (mouth, pharynx, esophagus,
stomach, small and large intestines, rectum) converts macromolecules
from food into smaller molecules that can be used by cells for energy
and for repair and growth.
4.2 Explain how the circulatory system (heart, arteries, veins, capillaries, red
blood cells) transports nutrients and oxygen to cells and removes cell
wastes. Describe how the kidneys and the liver are closely associated
with the circulatory system as they perform the excretory function of
removing waste from the blood.
4.3 Recognize that kidneys remove nitrogenous wastes, the liver removes
many toxic compounds from blood, and the spleen recovers as
hemoglobin from non-functioning red blood cells.
4.4 The presence of foreign particles initiates an immunological response.
This includes the recognition by and activation of several white blood
cells(B & T cells, macrophages, platelets)
4.5 Explain how the respiratory system (nose, pharynx, larynx, trachea,
lungs, alveoli) provides exchange of oxygen and carbon dioxide.
4.6 Explain how the nervous system (brain, spinal cord, sensory neurons,
motor neurons) mediates communication among different parts of the
body and mediates the body’s interactions with the environment. Identify
the basic unit of the nervous system, the neuron, and explain the
process of neuronal communication.
4.7 Explain how the muscular/skeletal system (skeletal, smooth and cardiac
muscles, bones, cartilage, ligaments, tendons) works with other systems
to support the body and allow for movement. Recognize that bones
produce blood cells.
4.8 Recognize that the sexual reproductive system allows organisms to
produce offspring that receive half of their genetic information from their
mother and half from their father, and that sexually produced offspring
resemble, but are not identical to, either of their parents.
4.9 Recognize that communication among cells is required for coordination
of body functions. The nerves communicate with electrochemical
signals, hormones circulate through the blood, and some cells produce
signals to communicate only with nearby cells.
4.10 Recognize that the body’s systems interact to maintain homeostasis.
Describe the basic function of a physiological feedback loop.
5. Evolution and Biodiversity
Central Concepts: Evolution is the result of genetic changes that occur in
constantly changing environments. Over many generations, changes in the
genetic make-up of populations may affect biodiversity through speciation and
extinction.
5.1
Explain how evolution is demonstrated by evidence from the fossil
record, comparative anatomy and embryology, genetics, molecular
4
5.2
5.3
5.4
5.5
5.6
5.7
5.8
biology, and examples of natural selection. This type of evidence can
also be used to demonstrate and classify evolutionary relationships in a
hierarchical manner.
Explore hierarchical relationships using bioinformatics tools designed to
analyze evolutionary classification and relationships. For example; online public bioinformatics tools like BLAST
(http://www.ncbi.nlm.nih.gov/BLAST) .
Describe an inherited trait as a physical expression of a gene. Explain
how mutations result in genetic and physical changes which can affect
the survival and reproductive success of an individual organism and
successive generations which carry the same mutations.
Explain how evolution, through natural selection can result in changes in
biodiversity through the increase or decrease of genetic diversity within a
population. Discuss factors that play a role in natural selection, i.e.;
genetic variability, environmental selective pressures, competition,
overproduction for available resources and reproductive success.
Provide evidence that evolution is not a static process and is occurring in
organisms today. Changes in viruses, antibiotic resistance of bacteria,
genes from genetically modified plants appearing in native plants,
resistance of insects to pesticides)
Provide evidence of environmental changes or pressures which result in
natural selection for or against some species.
Identify species as a reproductively distinct group of organisms, and how
natural selection can lead to speciation. Understand the effect of
geographic isolation and resource partitioning leading to unique species
(Australia, Galapagos Islands).
Explore the theory of evolution based on the mechanism of natural
selection as proposed by Darwin and Wallace. Explore additional the
scientific principles beyond those of Darwin and Wallace supporting the
theory of evolution.
6. Ecology
Central Concept: Ecology is the interaction among organisms and between
organisms and their environment.
6.1
6.2
6.3
6.4
Explain the energy flow within a food web: identify and distinguish
producers, consumers, and decomposers; the transfer of energy through
trophic levels.
Explain how water, carbon, and nitrogen cycle between abiotic
resources and organic matter in an ecosystem, and how oxygen cycles
through photosynthesis and respiration.
Examine and explain the path of a recyclable material from collection to
waste, reuse or recycling identifying the market forces.
Explain the effects on the environment and sustainability through the use
of renewable and nonrenewable resources.
5
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
Analyze the interdependence, limiting factors, and stability within an
ecosystem.
Describe how relationships among organisms (predation, parasitism,
competition, commensalisms, mutualism) add to the complexity of
biological communities.
Analyze changes in population size and biodiversity (speciation and
extinction) that result from: natural causes, climatic changes, human
activity and introduction of invasive species.
Explain how birth, death, immigration and emigration influence
population size.
Analyze the effect of natural resource conservation on a product over
time (e.g., automobile manufacturing, aluminum can recycling, paper
products).
Identify environmental health issues; visible and invisible pollutants and
explain their effects on human health.
Explain and compare short and long term, traditional and environmental
sound pest management practices may affect the environment.
Describe the ecosystems of watersheds and wetlands and the effects of
human activities on these ecosystems; e.g., the Chesapeake Bay.
Explain how man-made systems affect the environment; e.g.,
Deforestation greenhouse effect
7. Organismic Biology
Broad Concepts: The living world is very diverse. Beginning with the
simplest forms of life, the prokaryotes, to the most complex forms of life, the
eukaryotes, organisms differ in size, structure, how they survive, reproduce,
and evolve in their environments.
7.1
7.2
7.3
7.4
7.5
7.6
7.7
Differentiate between structures of prokaryotic and eukaryotic cells.
Already in 2.2?
Identify the characteristics of the three major Domains. I think we
reached a consensus that Domains were more relevant than Kingdoms
based on molecular bio?
Describe the methods of locomotion in microorganisms. (bacteria, algae,
protozoans)
Distinguish the methods of obtaining food among the microorganisms.
(autotrophic and hererotrophic) Is this covered by 2.3?
Describe the methods of asexual and sexual reproduction in the
microorganisms.
Explain the positive and negative roles that the microorganisms play in
their environments. (disease, decomposition, food chain, effect on
humans) Could this go into environmental?
Identify the characteristics of the bryophytes and tracheophytes. (ferns,
gymnosperms, and angiosperms)
6
7.8
Explain Alternation of Generations as the method of reproduction in the
fungi and each of the higher plant groups. Identify the reproductive
organs utilized by each group.
7.9 Identify the structural (cellular and organ) adaptations that provided for
the transition of plant life from the aquatic to the terrestrial environments.
If this section is too long, I might recommend removing this.
7.10 Describe the structure and function of each of the higher plant vegetative
organs. (roots, stems, and leaves)
7.11 Discuss how water and food are transported through the vascular plants.
Can this be combined with 7.10?
7.12 Describe the processes of pollination and (double??) I think just
fertilization would be OK. fertilization in the seed plants.
7.13 Differentiate between the invertebrate and vertebrate groups of animals.
Identify the major phyla of each group, their general characteristics, and
examples of each group.
7.14 Place the major animal phyla on a phylogenetic tree to demonstrate the
possible evolutionary relationships among the animal phyla.
7.15 Compare the advantages and disadvantages of symmetry (radial or
bilateral) in animals.
7.16 Trace the development of body plan in the invertebrates. [two layer ectoderm and endoderm, and three layer - ectoderm, endoderm, and
mesoderm (without and with coelom)]
7.17 Describe the structural and reproductive adaptations that led to the great
diversity and success of the insects in their environments.
7.18 Describe the evolutionary advances of early vertebrates that led to their
great diversity in all environments.
7.19 Describe the various forms of asexual and sexual reproductions
demonstrated by the members of the animal kingdom.
[7.9, 7.14, 7.17, 7.19 are very broad in scope. I think we need to evaluate if
this knowledge is 1) necessary for graduating high-school students and
2) if it is, can we make the objectives more precise.
Highlights in turquoise: Appropriate for high-school?]
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PHYSICAL SCIENCE
PHYSICS
Note: Certain Physics benchmarks are marked with an asterisk (*). These
asterisked benchmarks represent content that is recommended for all
students, but is required for those students who plan to continue with
Physics coursework at the college level and for many physics intensive
majors.
A. Motion and Forces
A1. Understand that motion can be described and analyzed conceptually and
quantitatively.
A1.1. Be able to describe the difference between scalar and vector quantities
and cite examples.
A1.2. Be able to compare and contrast the vector quantities (such as
displacement, velocity, acceleration, force, linear momentum) and scalar
quantities (distance, speed, energy, mass, work) that are used to describe
kinematics (the science of motion).
A1.3. Demonstrate a conceptual understanding of a reference frame by
explaining why one is needed when describing motion, and by using
reference frames to explain and represent the
relative motion of two objects.
A1.4. Demonstrate a conceptual understanding of average velocity, average
speed and average acceleration during intervals of time by determining
these quantities using tables and/or graphs of data representing position
versus time and velocity versus time.
*A1.5. Be able to analyze one-dimensional motion using the description of
position, velocity, and acceleration as functions of time, using algebraic
descriptions for simple motions (uniform
velocity or uniform acceleration).
A1.6. Be able to convert between the different sets of units (MKS, English,
etc.)often used in kinematics and dynamics.
A1.7. Be able to use dimensional analysis to predict the results of simple
problems and check the results of more challenging ones.
A2. Understand that Newton's laws of motion describe and predict the motion of
macroscopic objects, and be able to interpret and apply Newton’s three laws
of motion.
A2.1.Be able to add and subtract vectors graphically and algebraically in one
or more dimensions.
A2.2. Demonstrate understanding that a net force is required to alter an
object’s motion by describing how the magnitude of the object's
acceleration is proportional to the magnitude of the total applied force and
the direction of acceleration that of the total applied force.
A2.3. Be able to describe the concept of mass as inertia, i.e., as a measure of
resistance to change in motion by an applied force.
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A2.4. Be able to represent forces acting on a system of objects utilizing freebody diagrams.
*A2.5. Be able to use Newton's Laws to solve problems in static equilibrium,
and problem situations that yield constant acceleration.
A2.6. Be able to apply Newton's laws to free fall and projectile motion.
A2.7. Be able to describe motion in 2-D and 3-D as the net motion due to
independent motions in a rectangular coordinate system.
A2.8. Demonstrate conceptual understanding of the circular motion of an
object by describing the acceleration(s) it undergoes, and the forces that
produce these accelerations.
A2.9. Describe the nature of static and kinetic friction, and describe their
effects on motion.
A2.10. Describe Newton's law of universal gravitation in terms of the
attraction between two objects, their masses, and the distance between
them.
*A2.11. Be able to apply principles of rotational motion to solve problems
relating to angular momentum and torque.
B. Conservation of Energy and Momentum
B1. Understand that the law of conservation of energy provides an alternate
approach that can be used to predict and describe the motion of objects.
B1.1. Be able to explain work as being due to the action of a force on an
object undergoing a displacement.
B1.2. Be able to describe using appropriate examples how energy can be
converted from gravitational potential energy to kinetic energy and vice
versa.
B1.3. Demonstrate an understanding of the law of conservation of energy in
mechanical systems by using this law to solve for kinematic variables in
appropriate problem situations.
B1.4. Be able to describe both qualitatively and quantitatively how work can
be expressed as a change in mechanical energy.
B1.5. Be able to describe both qualitatively and quantitatively the concept of
power as work done per unit time.
B2. Understand that the law of conservation of momentum provides a
complementary approach to the law of conservation of energy that can be
used to predict and describe the motion of objects.
B2.1. Be able to describe linear momentum as the product of mass and
velocity and understand the relationship between the momentum change
of an object and the forces acting on it.
B2.2. Demonstrate an understanding of the conditions for which momentum is
conserved by applying momentum conservation methods in appropriate
situations (e.g. those involving collisions).
B2.3. Demonstrate a conceptual understanding of the difference between the
laws of conservation of momentum and conservation of energy by
describing the conditions under which one law or the other, or both, apply.
9
C. Heat and Heat Transfer
C1. Understand that heat is energy that is transferred between objects or
regions that are at different temperatures, by the processes of convection,
conduction, and radiation.
C1.1. Explain qualitatively how heat energy is transferred by the processes of
convection, conduction, and radiation.
C1.2. Explain how heat energy will move from an object at higher temperature
to one at lower temperature until equilibrium is reached. Apply to
understand everyday phenomena or technological applications, such as
how a thermos bottle or insulation works.
C2. Understand the concept of energy conservation (First Law of
Thermodynamics) and use it to relate various forms of energy.
C2.1. Describe the relationship between average molecular kinetic energy
and temperature. Understand that heat energy consists of the random
motion and vibrations of atoms, molecules, and ions.
C2.2. Explain the relationships between the temperature change in a
substance for a given amount of heat transferred, the amount (mass) of
the substance, and the specific heat.
C2.3. Describe the difference between energy and power. Be able to convert
between the many units used to describe both energy and power. Use
such conversions to discuss the amount of energy (in various forms)
contained in disparate systems.
C2.4. Describe the various sources of energy used in society.
*C2.5. Demonstrate a qualitative understanding of the Second Law of
Thermodynamics by describing the Law and the limits it places on the
efficiency of devices such as refrigerators and engines.
D. Waves
D1. Understand that waves carry energy from place to place without the transfer
of matter.
D1.1. Describe the properties of simple harmonic motion of an object from a
basic mechanics viewpoint, and how the period, frequency, and amplitude
of motion are determined by the conditions and material properties of the
object.
D1.2. Describe the measurable properties of waves (speed, frequency,
wavelength, amplitude, and period)and explain the relationships among
them.
D1.3. Describe the differences between standing and traveling waves in
mechanical systems and cite examples.
D1.4. Describe the differences between transverse and longitudinal waves in
mechanical systems and cite examples.
D1.5. Recognize the effects of media on the speed of a mechanical wave by
explaining that mechanical waves move faster through a solid than
through a liquid and faster through a liquid than through a gas.
D1.6. Describe the differences between mechanical waves (especially sound)
and electromagnetic waves, especially including their propagation speeds.
10
D1.7. Demonstrate an understanding of the basic interactions of waves with
matter by describing reflection and refraction.
D1.8. Explain how changes in the wavelength and frequency of waves as
they pass through media affect the propagation of the waves.
D1.9. Describe the apparent change in frequency of waves due to the motion
of a source or observer (the Doppler effect) and cite examples from
everyday life or use in technological applications, such as radar guns.
D1.10. Be able to apply basic wave concepts to understand everyday
phenomena or technological applications, such as ultrasound and sonar.
E. Electromagnetism
E1. Understand that stationary and moving charged particles result in the
electrical and magnetic phenomena.
E1.1. Be able to describe the attractive and repulsive electrostatic forces
between objects in terms of their charges and the distances between
them, as described by Coulomb’s law.
E1.2. Be able to compare and contrast the forms of Newton’s law of gravity
(between two masses) and Coulomb’s law (between two charges) in terms
of their functional form (inverse square laws) and magnitudes. Be able to
explain that gravitational forces play a more important role in macroscopic
systems than electrical forces due to the overall charge neutrality of
matter.
E1.3. Demonstrate a conceptual understanding of the differences between
insulators and conductors by explaining how electric charge tends to be
static on insulators and can move on the surface of and inside conductors.
E1.3a. Be able to explain that energy can produce a separation of
charges, with a subsequent change in electrostatic potential
energy.
E1.3b. Demonstrate a conceptual understanding of electric potential
(voltage) as a potential energy per unit of charge.
E1.4. Explain how electric current is a flow of charge caused by a difference
in electric potential (voltage) and that power dissipation is given by the
product of current and voltage.
E1.5. Be able to describe a qualitative and quantitative understanding of
current, voltage, resistance and the connection between them, as
described by Ohm's law.
E1.6. Be able to recognize circuit symbols and the common circuit elements
(battery, wires, resistance) in a schematic diagram.
E1.7. Be able to predict qualitatively how different combinations of
components such as batteries, light bulbs, and switches will behave in
series and parallel configurations.
*E1.8. Be able to analyze simple arrangements of electrical components, in
both series and parallel configurations.
E1.9. Apply concepts related to electricity and circuits to understand everyday
phenomena or technological applications, such as batteries, household
circuitry, and power grids.
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*E1.10. Recognize that moving electric charges create (and experience)
magnetic forces and moving magnets produce electric forces. Recognize
that the interplay of electric and magnetic forces form the basis for the
operation of electric motors, generators, and other technologies.
F. Electromagnetic radiation
F1.
Understand concepts dealing with electromagnetic waves
F1.1. Recognize that electromagnetic waves are transverse waves and travel
at the speed light (in vacuum).
F1.2. Describe the electromagnetic spectrum in terms of frequency and
wavelength, and identify the location of radio waves, microwaves, infrared
radiation, visible light (rainbow spectrum), ultraviolet rays, x-rays, and
gamma rays.
F1.3. Apply concepts of electromagnetic waves to understand everyday
phenomena or technological applications, such as radio, microwave, and
X-ray devices.
F2.
Understand the physics underlying the use of optical instruments.
F2.1. Using diagrams, describe the interactions of electromagnetic waves
(especially light) and matter leading to the phenomena of refraction and
reflection.
*F2.2. Demonstrate an understanding of how refraction and reflection effects
are used in the design and performance of optical instruments by solving
basic geometric optics problems consisting of mirrors, microscopes,
telescopes, etc.
CHEMISTRY
Overview: Chemistry is the study of matter – its properties, the changes
it goes through, and the underlying structure that helps us account for the
specific properties and possible changes. There are two separate
contexts in which students encounter the impact of chemistry in their lives:
The context of their interactions with matter as part of their everyday
experiences and the context of their study of this field in their educational
experiences. This set of standards attempts to recognize and address
these different contexts. As a result, there are those standards for which
all students are expected to achieve proficiency in order to produce a
citizenry scientifically literate with relation to chemistry [these standards
are identified by a “B” in brackets, for basic]; there are also those
standards for which students who will be pursuing math- / science-related
careers are expected to achieve proficiency in order to prepare them for
studies at the ‘next level’ [these standards are identified by an “A” in
brackets, for advanced]. It is important for the users of this document to
understand that the organization of the content topic areas (e.g. The
Macroscopic Realm of Matter, An Atomic Perspective, Heat, and Phase
Change) reflects arbitrary conceptual divisions and does not necessarily
indicate the way a particular chemistry course should be organized. For
instance, instead of completely separating the macroscopic perspective of
12
matter from the atomic molecular view, it makes pedagogical sense to
constantly intertwine the two so that students may become more ‘fluent’ in
moving back and forth between the two realms.
A. The Macroscopic Realm of Matter
A.1. Interpret the warning labels on reagent bottles and household chemicals
to identify potential dangers in both the use and the interactions with
other materials of the substance present in the container. [B]
A.2. Explain the properties of materials (e.g. density, melting point,
conductivity, corrosiveness), describe their relative utility in
characterizing materials, and use them to determine the identity of
unknown substances. [B]
A.3. Select and use measurement devices properly (including identification of
appropriate units and reading to correct significant figures) to obtain
quantitative information about the properties of a material (e.g. mass,
volume, etc.). [B]
A.4. Convert property information about a material into a properly-constructed
graph and analyze/interpret the graph to obtain additional information
(such as density from the mass-volume graph of a pure substance). [B]
B. Gases and the Beginnings of a Microscopic Perspective
B.1. Identify the relationships between the physical properties of gases (e.g.
pressure and volume as stated in Boyle’s Law) and describe methods for
the chemical preparation of gases (e.g. how oxygen can be prepared by
the catalyzed decomposition of hydrogen peroxide). [B]
B.2. Apply the principles behind various gas-law relationships to explain
everyday / familiar phenomena (e.g. Boyle’s Law to explain how we drink
through a straw or Charles’ Law to explain the flight of a hot-air balloon).
[B]
B.3. Explain the Law of Conservation of Mass (and its implications in terms of
recycling) and the Law of Definite Proportions (and its implications in
terms of a definition of compound) and describe how these principles –
along with the study of gases – lead to the development of the first
modern atomic theory. [B]
B.4. Identify the main points of the Kinetic Molecular Theory [B] and use them
to explain the various relationships between the physical properties of
gases. [A]
B.5. Perform calculations with the Combined Gas Law / Ideal Gas Law. [A]
C. An Atomic Perspective, Heat, and Phase Change
C.1. Identify the main points of Dalton’s Atomic Theory and how these can be
used to define elements and compounds; describe Dalton’s model of the
atom, its limitations, and its usefulness in accounting for the Kinetic
Molecular Theory. [B]
C.2. Describe the atomic / molecular differences between solids, liquids, and
gases using the Kinetic Molecular Theory and explain what happens at
13
the atomic / molecular level as a pure substance goes through phase
transitions. [B]
C.3. Distinguish between heat and temperature both at the macroscopic level
(heat is extensive while temperature is intensive) and at the microscopic
level (heat involves both the motion and position of atoms/molecules
while temperature measures only motion); identify the direction of heat
transfer (into – i.e. endothermic – and out of – i.e. exothermic – a
system) during various physical and chemical changes of matter. [B]
C.4. Explain entropy in terms of the level of atomic / molecular freedom or the
available probability states in a system [B] and use the tendency of
nature towards high entropy to predict the spontaneity of physical /
chemical processes. [A]
C.5. Describe the molecular nature of a closed system that has established a
dynamic equilibrium – particularly one involving two different phases of
matter [B] – and use this concept to explain why the melting point and
freezing point (as well as the boiling point and liquefaction point) are the
same for a pure substance. [A]
D. Atomic Structure and Radioactivity
D.1. Describe Thomson’s and Rutherford’s models of the atom, the
experiments leading to each, and the limitations and usefulness of each
model (Thomson’s model in terms of accounting for electrical
phenomena and Rutherford’s in terms of explaining radioactivity). [B]
D.2. Identify the major subatomic particles [protons, neutrons, and electrons],
describe the properties of each, and explain the way they interact to
control the physical, chemical and nuclear properties of atoms. [B]
D.3. Explain what isotopes are in terms of the major subatomic particles,
identify how isotopes of the same element relate to each other and
explain how isotopes are used in certain applications such as medical
diagnostic studies. [B]
D.4. Distinguish between radiation and radioactivity (including explaining why
the radiation from radioactive materials is so dangerous), identify the
atomic source of radioactive decay, [B] and explain the role that the four
forces of nature (gravity, electromagnetic, weak, and strong) play (or
don’t play) in radioactive processes. [A]
D.5. Describe / represent different decay / nuclear processes (including
fission and fusion) and explain industrial, medical, military applications
that are based on the properties of the particles produced by these
processes (e.g. the use of alpha radiation to reduce static electricity in
copier machines). [A]
D.6. Explain the concept of half-life in terms of the unpredictability of
radioactive decay processes [B] and describe the implications of the
half-life concept in terms of the relative danger of isotopes and the
technique of radioactive dating. [A]
E. Patterns, Organizing the Elements, and Periodicity
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E.1. Use the history of attempts to group the elements (e.g. Dobereiner’s Law
of Triads, Newland’s Law of Octaves) to account for the organizational
pattern on the modern periodic table, particularly its emphasis on
chemical properties over physical ones. [B]
E.2. Identify structural features of the standard version of the periodic table
(e.g. periods, groups, etc.) and explain how those might be used in
generating information about an element. [B]
E.3. Distinguish between metals, non-metals and metalloids and use the
format of the periodic table to classify an element into these groups. [B]
E.4. Use the periodic table and a knowledge of its structure to predict the
properties of unknown elements (e.g. element 115) and to identify trends
in such characteristics as size, reactivity, etc. [B]
E.5. Describe Bohr’s model and use it to give a simplified account of why
elements in the same group have similar properties and why atoms of
elements become larger as you go down a family. [B]
F. Chemical Bonding
F.1. Describe the macroscopic differences between covalent and ionic
compounds and how those differences can be accounted for in terms of
the atomic processes producing these different types of bonds; use
Lewis structures and Lewis dot diagrams to provide simple
representations of covalent and ionic bonding processes. [B]
F.2. Determine the formulas for both simple covalent and ionic compounds
based on the positions of the combining elements on the periodic table
and trends in combining ratios. [B]
F.3. Explain the concept of electronegativity and use it as a tool to explain the
presence of charges in bonds and as a first-order explanation of the
difference between covalent and ionic compounds. [B]
F.4. Explain the concepts of ionization energy and electron affinity and
describe / explain trends down and across the periodic table in these
properties as well as electronegativity. [A]
F.5. Describe what a bond energy (enthalpy) value represents and use a
table of these values to account for patterns of reactivity and to predict
reactions likely to be spontaneous. [A]
G. Ionic / Molecular Structure and the Structure-Property Relationship
G.1 Predict the shapes of simple molecules through the use of Valence Shell
Electron Repulsion (VSEPR) Theory; identify some basic crystal
structures for simple ionic compounds. [B]
G.2. Explain how electronegativity differences and molecular symmetry
determines whether a molecule is polar or non-polar (especially
molecules like water, NH3, CO2, etc.). [B]
G.3. Distinguish between chemical bonds and forces of attraction and the
impact each has on the physical and chemical properties of a substance.
[B]
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G.4. Describe the relationship between the strength of forces of attraction and
the physical properties of a substance such as boiling point and
solubility. [B]
G.5. Analyze a molecule to identify its attractive forces and use this analysis
to predict some of the physical properties of the molecule. [A]
H. Solutions and Acids and Bases, Part I
H.1. Identify the properties of solutions (including important colligative
properties) and describe a microscopic picture that accounts for at least
some of these. [B]
H.2. Identify the species present in a simple solution system (including
important polyatomic ions) and describe how these affect the physical
(especially conductivity) and chemical (such as the kinds of reactions
possible) properties of that system. [B]
H.3. Use qualitative terms (unsaturated, concentrated, etc.) to describe the
concentration of a solution [B]; perform calculations to determine
quantitatively the concentration of a solution (e.g. % weight, molarity,
normality) given the appropriate information [A].
H.4. Identify examples of acids and bases and describe one or more models
(e.g. Arrhenius, Brönsted-Lowry, or Lewis) that explain the properties of
each of these two classes. [B]
H.5. Identify examples of weak and strong acids and bases and connect this
classification to the way each is used / handled (e.g. certain weak acids
are found in food products; strong laboratory acids must be handled with
great caution) [B]; use one of the acid-base models/theories to account
for the molecular differences between weak and strong acids [A].
H.6. Explain what the pH scale measures, describe the significance of the
fact that it is a logarithmic scale, and connect pH values for a common
material (e.g. vinegar or baking soda) to its properties / uses [B]; use the
concept of pH to explain buffers [A].
I. Chemical Reactions, Oxidation-Reduction, and Acids and Bases, Part II
I.1. Interpret the symbols used in chemical reactions such as subscripts,
coefficients, states of matter, heat, equilibrium, etc. [B]
I.2. Explain why a chemical reaction must be balanced and the significance
of the final set of coefficients [B]; determine the values required to
balance an equation and connect these values to a microscopic
representation of the reaction. [A]
I.3. Identify basic types of chemical reactions (e.g. decomposition, single
replacement) [B]; use the understanding of reactions types to identify
likely products of simple chemical reactions. [A]
I.4. Identify important examples of acid-base neutralization reactions (e.g.
the chemistry of antacid tablets) and of oxidation-reduction reactions
(e.g. the chemistry of batteries) [B]; describe similarities and differences
between these two types of reactions (e.g. both involve an exchange of
a particle; one involves exchange of H+ and one exchange of e--) [A].
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I.5.
I.6.
I.7.
Explain what is meant by the mole being an amount unit that ‘bridges’
mass and number of particles [B]; perform calculations involving
conversions between mass, mole, and number of particles, including
stoichiometry calculations [A].
Describe the factors that make a reaction favorable (negative enthalpy,
positive entropy) or unfavorable and analyze simple reactions for these
factors. [A]
Apply the concept of dynamic equilibrium to chemical reactions by
indicating the species that would be present in an equilibrium state of a
reaction and explaining the effect of a stress on an equilibrium. [A]
J. A Modern View of Matter
J.1. Identify some of the modern instruments (e.g. STM, AFM) used to study
matter at the atomic / nanometer scale and what it means to ‘see’ atoms
with such instruments. [B]
J.2. Describe what the idea of particle-wave duality indicates about the
nature of an electron in our modern view; explain how the modern model
replaces the idea of predictability for an electron with the notion of
probability. [B]
J.3. Use the modern model to qualitatively describe how light interacts with
matter, including the idea of ground states and excited states. [A]
J.4. Connect features of the modern model of the atom (e.g. the s, p, d, and f
subshells) with structural features of the periodic table (e.g. the blocks of
elements in the standard version) [B]; use the format of the periodic table
to write electron configurations for main group elements and transition
metals [A].
17
SCIENTIFIC INQUIRY: UNIFYING PRINCIPLES
1. Systems, Order, and Organization
In the final analysis, the main objective of science is to study systems: To
characterize them, detail their structure, describe their order and explain
their organization. The term system and its implications are,
unfortunately, often not explicitly addressed with students, despite the fact
that this idea represents one of the first principles of science. Using
systems as a starting point for the set of unifying principles allows us to
justify the choices of the remaining principles and the grouping of them in
terms of their relationship with this central notion.
2. Form and Function
In order to have a starting point for studying systems that is simple and
accessible to the initially naïve viewpoint of students, teachers often focus
the conceptual attention on a single component of a system. That single
component then is analyzed in terms of its form and then that form is
connected with function. The interplay between form and function is
certainly central to biology, but it has an important place in the other
disciplines as well.
3. Measurement, Scale, and Tools
Any system can be explored at multiple levels. For instance a human
being can be explored at the level of organs as well as the cellular level or
even the molecular level. Those different levels often (but not always)
represent different scales of size; understanding the system at those
different scales requires understanding the differences in the
measurements used and the tools required to study the levels.
4. Energy, Change, and Equilibrium
One of the most fundamental attributes of a system is its tendency
towards change. That change is usually a result of a response to an
interaction with its environment. In the end, that change normally results
in a new state of constancy – an equilibrium – within the system in
relationship to its surroundings. Under- standing the forces that spur
change – particularly the influx or outflux of energy – and the way that the
system responds to that change is one of the most fundamental pursuits
of science.
5. Models, Patterns, and Explanations
How do we study and characterize all of these different aspects of a
system that were discussed above? This is part of the nature of the
scientific process. Two of the main cogs in that process are the
production of models and the recognition of patterns. Those models and
patterns or part of or lead to explanations of why the system has the
features that it does and how those features allow it to interact with its
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environment. Further, these explanations give us a way to make
predictions about a system, its unexamined characteristics and features of
its interaction with the surroundings that have been previously unexplored.
Additional Notes:
1. I recognize that what I have proposed here is highly similar to the NSES
notions of unifying principles. I am not trying to take credit for coming up
with this on my own because I have certainly read this document at some
point in my past. What I am suggesting, though, is a conceptual thread
that runs through the themes selected and helps us think in a rational way
about what to include and why, and about how to organize those things
we include.
2. There are a couple of items conspicuously missing from this list. Most
important are inquiry, environment, and technology. I address each one
of the separately below:
a. Inquiry is problematic. Amy pointed out an important distinction that I
have maintained in the list presented above: Each of the things in the
unifying principles list is an object of scientific study; inquiry appears
(to the extent that there is any agreement on what this term means) to
be the process by which that study is conducted. Based on that, it
would seem most appropriate to separate inquiry from the unifying
principles in a separate portion of the document. However, I would be
reluctant to title that section “Inquiry” as a result of the ambiguity of the
term and the fact that – as Bruce Smith (?) pointed out – it often has
connotations regarding pedagogy more than the process of science. It
would seem to make more sense to have a section titled “The Process
of Science” that describes many features of the nature of science that
have been established by groups such as NSES and Benchmarks.
Most important would be to present some clear definitions and
examples of terms such as hypothesis, theory, model, etc. so that
when they appear in the content standards, they would be used
unambiguously.
b. My opinion of Environment and Technology is that they should
represent a separate unifying theme category. This would allow one to
include ideas regarding how technological developments are related to
our understanding of systems, how systems dictate the design of
technology and how technology impacts the environment through its
effect on systems. I did not include this in the list above because my
stance did not seem to have much support in the group, making this
theme the most controversial.
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