ATOMIC STRUCTURE and nuclear reactions
Essential Question:
What happens when an atom breaks apart?
Enduring Understanding:
Nuclear processes, including fusion, fission and radioactive decays of unstable nuclei, involve release or absorption of energy. The total number of neutrons plus protons does not change in any nuclear processes.
Iowa Core Content Standard Correlation:
HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.
HS-PS1-8: Develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
HS-ESS1-1: Develop a model based on evidence to illustrate the life span of the sun and the role of nuclear fusion in the sun’s core to release energy in the form of radiation.
HS-ESS1-3: Communicate scientific ideas about the way stars, over their life cycle, produce elements.
Disciplinary Core Ideas:
Atoms of each element have unique structures.
An atom is the smallest unit of an element and is made mostly of empty space. The atom is composed of negatively charged electrons, which can leave the atom, and a positively charged nucleus that is made of protons and neutrons. The attraction of the electrons to the nucleus is the basis of the structure of the atom, thus each element has a unique structure arising from the interactions between electrons and their nuclei.
Other than the hydrogen and helium formed at the time of the Big Bang, nuclear fusion within stars produces all atomic nuclei lighter than and including iron, and the process releases electromagnetic energy. Heavier elements are produced when certain massive stars achieve a supernova stage and explode.
1.1. Atoms are composed of smaller particles that contribute mass, identity and charge.
Objectives:
(a.) Summarize the atomic theory and how and why our understanding of the atom has changed.
(b.) Draw and label a model of the atom, indicating the location and charge of the subatomic particles.
(c.) Predict the effect a change in the number of subatomic particles will have on the atom's mass, identity and charge.
1.2. The number of protons and the mass number define the type of atom.
Objectives:
(d.) Define isotope and compare the numbers of protons and neutrons in an isotope.
(e.) Determine the identity of an element based on a mass spectrometer graph.
(f.) Determine an atoms' atomic and mass number, number of protons, neutrons and electrons and write element symbols using XAZ notation.
1.3. Unstable atoms emit radiation to gain stability.
Objectives:
(g.) Explain and model why some nuclei are unstable based on the interactions between the weak and strong nuclear forces.
(h.) Summarize how radioactivity was discovered and studied and explain the relationship between unstable nuclei and radiation.
(i.) Apply the law of conservation of mass to balance nuclear equations.
Links/Sources:
Sections 4.4, 24.1
(Link) Weak Nuclear Force
(Link) Strong Nuclear Force
1.4. Nuclear reactions include fusion, fission and radioactive decay.
Objectives:
(j.) Summarize, compare, contrast and model examples of nuclear reactions (fission, fusion and radioactive decay).
(k.) Create and interpret a radiometric decay graph.
Links/Sources
Section 24.3
(Link) Nuclear fission v. fusion
Lab/Claim: Strawmium Radioactive Decay Rate
1.5. Elements can be formed through natural processes (stellar nucleosynthesis, cosmic rays, super nova) and artificial processes (particle accelerators).
Objectives:
(l.) Summarize how elements can be formed through natural and artificial processes.
(Link) Fusion game
(Link) Solar Fusion Game
(Video/Link) 60 Minutes "Inside the Big Bang Machine"
(Video/Link) 60 Minutes "The Collider"
1.6. Nuclear reactions have many useful applications, but they also have harmful biological effects.
Objectives:
(m.) Provide examples of the benefits and dangers of nuclear reactions.
Links/Sources:
Sections 4.4, 24.1
(Link) Sources of Radiation
Lab/Claim: Identifying an Unknown Radiation Source