BIO152H5 Chapter Notes - Chapter 2: Serpentine Soil, Valence Electron, Radiometric Dating
Document Summary
Chapter 2 the chemical context of life. Wood ants spray formic acid on enemies defense mechanism. Chemicals help in communication, defense, and mating. Electrons exist in orbits outside the nucleus. Dalton amu -> mass of neutron and proton. Electrons mass can be ignored when computing atomic mass. Trace elements are those needed by certain organisms in small quantities to survive. Serpentine soil contains elements that are poisonous to plants. A radioactive isotopes nucleus" will decay spontaneously and give off energy and protons, which may lead to the creation of an atom of a different element. Radioactive tracers: tracking atoms through metabolism, diagnosing kidney disorders, Radiation from decaying isotopes damages cellular molecules. Half-life of an isotope: time it takes for 50% of the parent isotope to decay (using process of radioactive dating) Matter tends to move to the lowest possible place with potential energy. An electron cannot exist between energy levels.
