Accelerated Biology Introduction to the Chemistry of Biology! Theme: Structure Meets Function

How does the structure of an atom affect its stability? Drawing an atom can predict the location and number of its: – Protons – Neutrons – Electrons – Valence Electrons

Stability Most elements on the periodic table are UNSTABLE! – Two ways to be unstable: Nuclear instability: – Isotopes with extra neutrons undergo radioactive decay. – Ex. Carbon-14 decays. How does carbon 14 differ from the carbon you drew? Valence electrons: – Stability=8 valence electrons – Atoms take, give away, or share to achieve stability. – When an atom takes or gives up valence electron it becomes an ion

Using structure to make predictions about function Draw the structure of the following atoms: – Magnesium, chlorine, oxygen, hydrogen, sodium – Use your drawing to identify: Protons Neutrons Electrons Valence Electrons What type of ION your element would form – Cation: positive ion—What does this mean in terms of e’s? – Anion: negative ion—What does this mean in terms of e’s?

Bonding: When two or more atoms combine to become stable: Two types of bonds hold atoms together within compounds: – Ionic – Covalent Make a Venn Diagram to compare and contrast. be sure to include examples relevant to living things.

Nuclear Stability: Scientists use the stability of the nucleus in many technology applications Isotope: TechnologyType of Isotope Used (one example) Description of the technology Application—How humans use this technology Radiation Therapy Radioactive Tracers/Imaging Radiometric Dating Smoke alarms Nuclear Fission Irradiation

Assessment: How does the structure of an atom give us clues about its function (reactivity) – In your answer use specific examples of atoms to show your understanding of how atomic structure allows for function!

Next steps! Carbon and Water How does the structure of water make life on earth possible? Preview Notes: Homework: Read section 2-3 for Thursday! In your notes identify 6 properties of water. Make a table with the following headings: PropertyDescriptionHow the structure of water allows this unique property Why this is important in living things: