• 9-12: 3C/H3. In deciding on proposals to introduce new technologies or curtail existing ones, some key questions arise concerning possible alternatives, who benefits and who suffers, financial and social costs, possible risks, resources used (human, material, or energy), and waste disposal.
• 9-12: 3C/H5. Human inventiveness has brought new risks as well as improvements to human existence.

• 6-8: 4D/M1a. All matter is made up of atoms, which are far too small to see directly through a microscope.
• 9-12: 4D/H1. Atoms are made of a positively charged nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. The nucleus is composed of protons and neutrons which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge.
• 9-12: 4D/H3. Although neutrons have little effect on how an atom interacts with other atoms, the number of neutrons does affect the mass and stability of the nucleus. Isotopes of the same element have the same number of protons (and therefore of electrons) but differ in the number of neutrons.
• 9-12: 4D/H4. The nucleus of radioactive isotopes is unstable and spontaneously decays, emitting particles and/or wavelike radiation. It cannot be predicted exactly when, if ever, an unstable nucleus will decay, but a large group of identical nuclei decay at a predictable rate. This predictability of decay rate allows radioactivity to be used for estimating the age of materials that contain radioactive substances.

• 6-8: 11B/M1. Models are often used to think about processes that happen too slowly, too quickly, or on too small a scale to observe directly. They are also used for processes that are too vast, too complex, or too dangerous to study.
• 6-8: 11B/M4. Simulations are often useful in modeling events and processes.

• 6-8: 11D/M3. Natural phenomena often involve sizes, durations, and speeds that are extremely small or extremely large. These phenomena may be difficult to appreciate because they involve magnitudes far outside human experience.

Radioactive decay happens when an atomic nucleus of an unstable atom loses energy by emitting ionizing radiation. This resource simulates alpha decay, in which the nucleus emits an alpha particle. It's much simpler to understand than beta decay, and a good place for beginners to start. Don't miss the Bucket o' Polonium activity, which will help kids understand half-life. Note: If kids want to know, "Why are we studying this?", it's interesting to note that thorium-powered concept cars feature a nuclear reactor that uses alpha decay. In theory, 8 grams of thorium could power a car for one million miles with zero emissions.

• Physical Sciences K-8 History and Discovery Unit
• Physics First History and Discovery Unit
• Conceptual Physics History and Discovery Unit
• Algebra-Based Physics History and Discovery Unit
• AP/Calculus-Based Physics History and Discovery Unit

Radioactive decay happens when an atomic nucleus of an unstable atom loses energy by emitting ionizing radiation. This resource simulates alpha decay, in which the nucleus emits an alpha particle. It's much simpler to understand than beta decay, and a good place for beginners to start. Don't miss the Bucket o' Polonium activity, which will help kids understand half-life. Note: If kids want to know, "Why are we studying this?", it's interesting to note that thorium-powered concept cars feature a nuclear reactor that uses alpha decay. In theory, 8 grams of thorium could power a car for one million miles with zero emissions.

• Physical Sciences K-8 Molecular Structures and Bonding Unit
• Physics First Molecular Structures and Bonding Unit
• Conceptual Physics Molecular Structures and Bonding Unit
• Algebra-Based Physics Molecular Structures and Bonding Unit
• AP/Calculus-Based Physics Molecular Structures and Bonding Unit