I. California K-6 Standards for Physical Science Basics

II. Goals of This Module

III. Electromagnetic Radiation

IV. Atoms

V. Motion, Heat, and Temperature

VI. Mechanisms of Heat Transfer

VII. Possible Essay Questions

VIII. Practice Questions

1. Grade 6
1. Heat (Thermal Energy) (Physical Science)
1. Heat moves in a predictable flow from warmer objects to cooler objects until all objects are at the same temperature. As a basis for understanding this concept, students know:
1. energy can be carried from one place to another by heat flow, or by waves including water waves, light and sound, or by moving objects.
2. when fuel is consumed, most of the energy released becomes heat energy.
3. heat flows in solids by conduction (which involves no flow of matter) and in fluids by conduction and also by convection (which involves flow of matter).
4. heat energy is also transferred between objects by radiation; radiation can travel through space.

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• To review those concepts of chemistry and physics that are necessary to the understanding of concepts in Earth science.
• To learn about radiation and heat energy and how it is transferred in the environment.

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• Definition - energy traveling in wave form throughout the Universe is referred to as electromagnetic radiation.
• Electromagnetic radiation is created by vibrations that occur within all objects in the universe.
• If things moving in wave form are interfered with, the interference waves that are produced will in places cancel each other out. Light waves traveling between a thumb and forefinger that are almost touching cause black, cancellation bands, thus proving that light (a form of electromagnetic radiation)is in wave form. (Try this yourself.)
• The transmission of these electromagnetic waves through space occurs at the speed of light (300,000 km/sec = 186,000 mi/sec).
• Various forms of electromagnetic radiation are recognized based on their wavelength. This range of radiation wavelengths is referred to as the electromagnetic spectrum.

Gamma rays
X rays
Ultraviolet rays
Visible light	0.001 mm wavelength
Infrared rays
Microwaves	1.0 cm wavelength
Radar waves
Short waves (FM, TV)	1.0 m wavelength
Broadcast radio waves (AM)	100.0 m wavelength
Long radio waves

• If a source of radiation is moving toward a receiver, the wavelength reaching the receiver is shortened. Likewise, if a source of radiation is moving away from a receiver, the wavelength reaching the receiver is lengthened. This phenomenon is similar to the change in pitch of a train whistle from high pitch (shortened sound waves) as the train approaches to a lower pitch (lengthened sound waves) as the train passes and moves away. This change in wavelength produced by a moving source of radiation is referred to as the Doppler effect.

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• Atoms are the fundamental building blocks of nature.
• It is important to know something about atoms in order to gain insight and an educated understanding of radioactivity and nuclear energy.
• Atoms are composed of:
• A nucleus - an area in the center of the atom which contains protons and neutrons.
• Plus, a cloud of electrons that move around the nucleus at various prescribed distances from it.
• The nucleus contains -
• Protons - subatomic particles that each have a total electrical charge of +1 and a mass (atomic weight) of 1.
• The number of protons in a nucleus determines:
• The atomic number of an atom, and
• The element that will be formed by the atom (such as hydrogen, oxygen, iron, copper, carbon, mercury, etc.).
• Neutrons - subatomic particles that each have a total electrical charge of 0 and a mass (atomic weight) of 1.
• The number of neutrons and protons in a nucleus determines:
• The mass number (atomic weight) of an atom (4 protons and 5 neutrons in a nucleus gives a mass number of 9 for the atom and produces the element beryllium).
• Electrons - subatomic particles that each have an electrical charge of -1 and no effective weight.
• Electrons occur at various energy levels away from the nucleus of the atom; the number of energy levels used in the atom depends on the number of electrons, which in an electrically balanced atom is equal to the number of protons.
• The highest energy level in an atom always desires to be filled with eight electrons, except for the first energy level which contains two.
• Isotopes - atoms of the same element which have different mass numbers due to the presence of a different number of neutrons.
• The common isotope of an element is usually stable, but some elements have unstable (radioactive) isotopes that emit certain kinds of radiation in an attempt to become stable.
• Ionic bonding -
• In order to fill its highest energy level, an atom will: Figure
• Give away four or less electrons to empty the highest level, thus leaving the next lower level filled, or
• Take in four or less electrons to fill the highest level.
• The result is called an ion and has either a:
• Positive electrical charge (excess protons) - a cation, or a
• Negative electrical charge (excess electrons) - an anion.
• Two or more ions, whose total positive charges are equal to their total negative charges, will attract each other and unite as a molecule. Many molecules of the same type, when joined together, produce a crystalline, chemical compound.
• Covalent and metallic bonding - atoms unite and share electrons to fill their highest energy level.
• Metallic bonding accounts for both the electrical conductivity of metals (because electrons move quickly between atoms) and for their ductility (because the atom can change shape easily).
• The Earth's eight most abundant elements -

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• Heat is produced by the motion of subatomic particles within a mass made of such particles; the faster the movement, the more heat is produced.
• The amount of heat is measured by the temperature of the mass of particles.
• If the mass has no motion within it, there is no heat and no temperature = zero degrees on the Kelvin scale (0°K)
• There are three scales for measuring temperature.
• Freezing point of water
• = zero degrees on the Celsius scale (0°C)
• = 273 degrees on the Kelvin scale (273°K)
• = 32 degrees on the Fahrenheit scale (32°F)
• Conversion charts and formulas are available for converting one scale to another.
• If more heat energy is being produced in one place than another, the heat energy will move or flow from the place of high heat toward low heat (from high temperature to low temperature).

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• Conduction - caused by collision of fast-moving atoms or molecules with slower ones, thus speeding up the slower ones; good in metals, poor in liquids and gases.
• Convection - caused by movement of a warm mass into a cooler place, thus warming the cooler place; good in liquids and gases, poor in metals.
• Radiation - caused by passage of electromagnetic waves through substances, thus speeding up the movement of subatomic particles.

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• Describe what you know about electromagnetic radiation and the various components of the electromagnetic spectrum.
• Explain the Doppler effect.
• Describe an atom and all of its components.
• Describe and illustrate how ionic and metallic bonding work.

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VIII. Practice Questions -

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