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Science - Physical Science

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Physical science is the term for the study of non-living systems, and includes physics and chemistry. The foundations of physical science rest upon key concepts and theories, each of which explains and/or models a particular aspect of the behavior of nature.

Physics includes describing and measuring motion; the theory of gravity; energy, work, and power; energy forms; kinetic molecular theory; the principles of waves and sound; the principles of electricity, magnetism, and electromagnetism; and the principles, sources, and properties of light.

Chemistry is the science of matter. Its studies include atomic theory; water and its properties; chemical elements, chemical reactions, and energy transformations; nuclear chemistry; and organic chemistry. In all areas of physical science the focus is on the application of the knowledge to solve real life problems. It is the use of the conceptual knowledge and not simply the knowledge itself that should form the core of this discipline. Physical science instruction must include the inquiry knowledge and skills described in the inquiry section of the Science Core Curriculum. Instruction should be engaging and relevant and strong connections must be made to students' lives.

 

Kindergarten-Grade 2

Essential Concepts and/or Skills

Understand and apply knowledge of observable and measurable properties of objects
Objects have many observable properties including size, weight, shape, color, temperature and the ability to react with other substances. Those properties can be measured using tools such as rulers, balances and thermometers.

Objects are made of one or more materials.

Objects can be described by the properties of the materials from which they are made. Properties can be used to separate or sort a group of objects or materials.

Understand and apply knowledge of characteristics of liquids and solids
Materials can exist in different states – solid, liquid, and gas.

Some common materials, such as water, can be changed from one state to another by heating or cooling.

Understand and apply knowledge of the positions and motions of objects
The position of an object can be described by locating it relative to its background.

An object’s motion can be described by observing and measuring its position over time.

An object’s position or movement can be changed by pushing or pulling.

 

Grades 3-5

Essential Concepts and/or Skills

Understand and apply knowledge of how to describe and identify substances based on characteristic properties
It may be necessary to use magnification to observe the component parts of some materials.

A substance has characteristic properties. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

The properties of a substance can be measured using tools and technology.

When a new material (compound) is made by chemically combining two or more materials, it has properties that are different from the original materials. For that reason, many different materials can be made from a small number of basic materials.

Understand and apply knowledge of states of matter and changes in states of matter
Materials can exist in different states – solid, liquid and gas. Some common materials can be changed from one state to another by heating or cooling.{/slide}

Understand and apply knowledge of the concept of conservation of mass/matter
When something is broken into parts, the parts have the same total mass as the original item.

Understand and apply knowledge of sound, light, electricity, magnetism, and heat
Sound is produced when vibrations from objects travel through a medium and are received. Sound can vary in volume. The pitch of a sound can be varied by changing the rate of vibration.

Light travels in a straight line until it strikes an object. Light can be reflected by a mirror, refracted by a lens, or absorbed by an object.

Electricity in circuits can produce light, heat, sound, and magnetic effects. Electricity can only flow through a closed circuit.

Magnets attract and repel each other and certain kinds of other materials.

Heat can be produced in many ways, such as burning, rubbing, or mixing one substance with another. Heat can move from one object to another by conduction.

Understand and apply knowledge of how forces are related to an object’s motion
The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph.

Changes in speed or direction of motion are caused by forces. The greater the force, the greater the change in motion. The more massive an object, the less effect a given force will have in changing its motion.

 

Grades 6-8

Essential Concepts and/or Skills

Understand and apply knowledge of

  • elements, compounds, mixtures, and solutions based on the nature of their physical and chemical properties.
  • physical and chemical changes and their relationship to the conservation of matter and energy.

A substance has characteristic properties, such as density, a boiling point, and solubility, all of which are independent of the amount of the sample. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

Substances react chemically in characteristic ways with other substances to form new substances (compounds) with different characteristic properties. In chemical reactions, the total mass is conserved. Substances often are placed in categories or groups if they react in similar ways; metals is an example of such a group.

Chemical elements do not break down during normal laboratory reactions involving such treatments as heating, exposure to electric current, or reaction with acids. There are more than 100 known elements that combine in a multitude of ways to produce compounds, which account for the living and nonliving substances that we encounter.

Understand and apply knowledge of forms of energy and energy transfer
Energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical. Energy is transferred in many ways.

Heat moves in predictable ways, flowing from warmer objects to cooler ones, until both reach the same temperature.

Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection). To see an object, light from that object- emitted by or scattered from it- must enter the eye.

Electrical circuits provide a means of transferring electrical energy when heat, light, sound, and chemical changes are produced.

In most chemical and nuclear reactions, energy is transferred into or out of a system. Heat, light, mechanical motion, or electricity might all be involved in such transfers.

The sun is a major source of energy for changes on the earth’s surface. The sun loses energy by emitting light. A tiny fraction of that light reaches the earth, transferring energy form the sun to the earth. The sun’s energy arrives as light with a range of wavelengths, consisting of visible light, infrared, and ultraviolet radiation.

Understand and apply knowledge of motions and forces
The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph.

An object that is not being subjected to a force will continue to move at a constant speed and in a straight line.

If more than one force acts on an object along a straight line, then the forces will reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in speed or direction of an object’s motion.

 

Grades 9-12

Essential Concepts and/or Skills

Understand and apply knowledge of the structure of atoms
Principles that underlie the concept and/or skill include but are not limited to:

  • Atomic structure

Matter is made of minute particles called atoms, and atoms are composed of even smaller components. These components have measurable properties, such as mass and electrical charge. Each atom has a positively charged nucleus surrounded by negatively charged electrons. The electric force between the nucleus and electrons holds the atom together.

  • Atomic nucleus (composition and size)
  • Isotopes (related to relative mass)

The atom's nucleus is composed of protons and neutrons, which are much more massive than electrons. When an element has atoms that differ in the number of neutrons, these atoms are called different isotopes of the element.

  • Nuclear forces: Fission and Fusion

The nuclear forces that hold the nucleus of an atom together, at nuclear distances, are usually stronger than the electric forces that would make it fly apart. Nuclear reactions convert a fraction of the mass of interacting particles into energy, and they can release much greater amounts of energy than atomic interactions. Fission is the splitting of a large nucleus into smaller pieces. Fusion is the joining of two nuclei at extremely high temperature and pressure, and is the process responsible for the energy of the sun and other stars.

  • Radioactive isotopes
  • Predictable rates of decay

Radioactive isotopes are unstable and undergo spontaneous nuclear reactions, emitting particles and/or wavelike radiation. The decay of any one nucleus cannot be predicted, but a large group of identical nuclei decay at a predictable rate. This predictability can be used to estimate the age of materials that contain radioactive isotopes.

Understand and apply knowledge of the structure and properties of matter
Principles that underlie the concept and/or skill include but are not limited to:

  • Valence electrons
  • Chemical bonds

Atoms interact with one another by transferring or sharing electrons that are the furthest from the nucleus. These outer electrons govern the chemical properties of the element.

Principles that underlie the concept and/or skill include but are not limited to:

  • Periodic table
  • Periodic trands

An element is composed of a single type of atom. When elements are listed in order according to the number of protons (called the atomic number), repeating patterns of physical and chemical properties identify families of elements with similar properties. This “Periodic Table” is a consequence of the repeating pattern of outermost electrons and their permitted energies.

Principles that underlie the concept and/or skill include but are not limited to:

  • Molecular and ionic structures
  • Physical properties of chemical compounds

Bonds between atoms are created when electrons are paired up by being transferred or shared. A substance composed of a single kind of atom is called an element. The atoms may be bonded together into molecules or crystalline solids. A compound is formed when two or more kinds of atoms bind together chemically.

Principles that underlie the concept and/or skill include but are not limited to:

  • States of matter
  • Relationship between pressure and volume of gases

Solids, liquids, and gases differ in the distances and angles between molecules or atoms and, therefore, the energy that binds them together. In solids the structure is nearly rigid; in liquids molecules or atoms move around each other but do not move apart; and in gases molecules or atoms move almost independently of each other and are mostly far apart.

Principles that underlie the concept and/or skill include but are not limited to:

  • Hydrocarbon compounds

Carbon atoms can bond to one another in chains, rings, and branching networks to form a variety of structures, including synthetic polymers, oils, and the large molecules essential to life.

Understand and apply knowledge of chemical reactions
Principles that underlie the concept and/or skill include but are not limited to:

  • Conservation of matter
  • Common reactions

"Chemical reactions" is an essential concept of a world-class secondary science curriculum. Included in "chemical reactions" is the following content:
Chemical reactions occur all around us, for example in health care, cooking, cosmetics, and automobiles. Complex chemical reactions involving carbon-based molecules take place constantly in every cell in our bodies.

  • Thermochemistry

Chemical reactions may release or consume energy. Some reactions such as the burning of fossil fuels release large amounts of energy by losing heat and by emitting light. Light can initiate many chemical reactions such as photosynthesis and the evolution of urban smog.

  • Types of reactions
  • Acids and bases
  • Common reactions in living systems

A large number of important reactions involve the transfer of either electrons (oxidation/reduction reactions) or hydrogen ions (acid/base reactions) between reacting ions, molecules, or atoms. In other reactions, chemical bonds are broken by heat or light to form very reactive radicals with electrons ready to form new bonds. Radical reactions control many processes such as the presence of ozone and greenhouse gases in the atmosphere, burning and processing of fossil fuels, the formation of polymers, and explosions

  • Reaction rates and equilibrium

Chemical reactions can take place in time periods ranging from the few femtoseconds (10-15 seconds) required for an atom to move a fraction of a chemical bond distance to geologic time scales of billions of years. Reaction rates depend on how often the reacting atoms and molecules encounter one another, on the temperature, and on the properties--including shape--of the reacting elements.

Understand and apply knowledge of motions and forces
Principles that underlie the concept and/or skill include but are not limited to:

  • Motions
  • Forces
  • Newton’s Laws

Objects change their motion only when a net force is applied. Laws of motion are used to calculate precisely the effects of forces on the motion of objects. The magnitude of the change in motion can be calculated using the relationship F = ma, which is independent of the nature of the force. Whenever one object exerts force on another, a force equal in magnitude and opposite in direction is exerted on the first object.

  • Gravitation
  • Mass vs weight

Gravitation is a universal force that each mass exerts on any other mass. The strength of the gravitational attractive force between two masses is proportional to the masses and is inversely proportional to the square of the distance between them.

  • Electric & magnetic forces

The electric force is a universal force that exists between any two charged objects. Opposite charges attract while like charges repel. The strength of the force is proportional to the charges, and, as with gravitation, inversely proportional to the square of the distance between them.

Between any two charged particles, electric force is vastly greater than the gravitational force. Most observable forces such as those exerted by a coiled spring or friction may be traced to electric forces acting between atoms and molecules.

Electricity and magnetism are two aspects of a single electromagnetic force. Moving electric charges produce magnetic forces, and moving magnets produce electric forces. These effects help students to understand electric motors and generators.

Understand and apply knowledge of conservation of energy and increase in disorder
Principles that underlie the concept and/or skill include but are not limited to:

  • Types of energy
  • Energy transformations
  • Conservation of energy

"Conservation of energy and increase in disorder" is an essential concept of a world-class secondary science curriculum. Included in "conservation of energy and increase in disorder" is the following content:
The total energy of the universe is constant. Energy can be transferred by collisions in chemical and nuclear reactions, by light waves and other radiations, and in many other ways. However, it can never be destroyed. As these transfers occur, the matter involved becomes steadily less ordered.

All energy can be considered to be either kinetic energy, which is the energy of motion; potential energy, which depends on relative position; or energy contained by a field, such as electromagnetic waves.

Understands and applies knowledge of interactions of energy and matter
Principles that underlie the concept and/or skill include but are not limited to:

  • Wave phenomena
  • Energy and matter
  • Electromagnetic waves

"Interactions of energy and matter" is an essential concept of a world-class secondary science curriculum. Included in "interactions of energy and matter" is the following content:
Waves, including sound and seismic waves, waves on water, and light waves have energy and can transfer energy when they interact with matter.

Electromagnetic waves result when a charged object is accelerated or decelerated. Electromagnetic waves include radio waves (the longest wavelength), microwaves, infrared radiation (radiant heat), visible light, ultraviolet radiation, x-rays, and gamma rays. The energy of electromagnetic waves is carried in packets whose magnitude is inversely proportional to the wavelength.

Printed from the Iowa Department of Education website on April 21, 2014 at 3:54am.