1 / 19

UNIT FOUR: Matter and its Changes

UNIT FOUR: Matter and its Changes. Chapter 12 Atoms and the Periodic Table Chapter 13 Compounds Chapter 14 Changes in Matter Chapter 15 Chemical Cycles and Climate Change. Chapter Fourteen: Changes in Matter. 14.1 Chemical Reactions 14.2 Types of Reactions

hestia
Download Presentation

UNIT FOUR: Matter and its Changes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. UNIT FOUR: Matter and its Changes • Chapter 12 Atoms and the Periodic Table • Chapter 13 Compounds • Chapter 14 Changes in Matter • Chapter 15 Chemical Cycles and Climate Change

  2. Chapter Fourteen: Changes in Matter • 14.1 Chemical Reactions • 14.2 Types of Reactions • 14.3 Energy and Chemical Reactions • 14.4 Nuclear Reactions

  3. Chapter 14.4 Learning Goals • Compare and contrast chemical and nuclear reactions. • Explain the significance of the strong nuclear force. • Explore benefits and negative effects of nuclear reactions.

  4. 14.4 Chemical vs. Nuclear Reactions • The involvement of energy in chemical reactions has to do with the breaking and forming of chemical bonds. • A nuclear reaction involves altering the number of protons and/or neutrons in an atom.

  5. 14.4 Chemical vs. Nuclear Reactions • For complex reasons, the nucleus of an atom becomes unstable if it contains too many or too few neutrons relative to the number of protons. • The forces inside the atom result in it breaking apart or releasing particles.

  6. 14.4 Radioactivity • Almost all elements have one or more isotopes that are stable. • “Stable” means the nucleus stays together. • Carbon-14 is radioactive because it has an unstable nucleus.

  7. 14.4 Radioactive Decay • This process of radioactive decay results in an unstable, radioactive isotope like carbon-14 becoming the more stable isotope nitrogen-14.

  8. 14.4 Radioactive Decay • There are three types of radioactive decay: • alpha decay, • beta decay, and • gamma decay.

  9. 14.4 Two types of Nuclear Reactions • There are two kinds of nuclear reactions: fusion and fission. • Nuclear fusion is the process of combining the nuclei of lighter atoms to make heavier atoms.

  10. 14.4 Fusion • Nuclear fusion occurs in the Sun and the resulting energy released provides Earth with heat and light.

  11. 14.4 Types of Nuclear Reactions • Nuclear fission is the process of splitting the nucleus of an atom. • A fission reaction can be started when a neutron bombards a nucleus.

  12. 14.4 Using nuclear reactions in medicine and science • A half-life is a certain length of time after which half of the amount of radioactive element has decayed. • As a radioactive element decays, it emits harmful radiation such as alpha and beta particles and gamma rays.

  13. 14.4 Using nuclear reactions • Radioactive dating is a process used to figure out the age of objects by measuring the amount of radioactive material in it and by knowing the half-life of that substance. • Understanding radioactive decay of uranium-238 has allowed scientists to determine that the age of Earth is 4.6 billion years old.

  14. 14.4 Using nuclear reactions in medicine and science • Radioisotopes(also called radioactive isotopes) are commonly used as tracers in medicine and science. • By adding a radioactive isotope into a system (such as the human body or an underground water supply), problems can be detected.

  15. Key Question: Can we measure the heat released/energy absorbed by instant hot and cold packs? Investigation 14C Types of Chemical Reactions

  16. Hydrogen Powered Cars • Scientists and engineers from government agencies, universities, and all of the major automobile manufacturers are designing, building, and testing hydrogen fuel cell vehicles, also known as FCVs.

More Related