Ionic bonds are formed when some electrons the valence shell of an atom connects with gaps in another atom's valence shell to make the desired 8.
What are covalent bonds?
When two atoms share one or more pairs of valence shell electrons.
What is the pH scale?
The pH scale is a measuring scale for acidic/basic levels in certain substances. It goes from 0 to 14, 7 being neutral. High acids are closer to 0 and high bases are closer to 14. For a point of reference, human blood is neutral.
The Facts:
-The four most abundant elements in the human body are oxygen, carbon, hydrogen and nitrogen
-Hydrogen bonds are weak, but contribute to many of the emergent properties of water
-Acids have high concentrations of H+ (hydrogen ions)
-Bases have high OH- (hydroxide ions)
-Blood is considered and aqueous solution
Some Key Terms:
-Matter: Anything that occupies space and has mass
-Element: A substance that cannot be broken down into another
-Compound: a substance consisting of two or more different elements combined in a fixed ratio
-Proton: A subatomic particle with a positive charge
-Electron: A subatomic particle with a negative charge that orbits the proton
-Neutron: A subatomic particle that makes up the nucleus of an atom with a neutral charge
-Atomic Number: The number of protons in an atom
-Mass Number: The sum of the neutrons and protons in an atom
-Isotopes: An atom with a different number of neutrons
-Radioactive Isotope: An isotope in which the nucleus decays, giving off energy
This is a drawing of the pH scale, the word "base" being interchangeable with "alkaline"
Summary:
This chapter was but a mere introduction into the chemistry-based side of biology. It incorporated the chemical basis in basic functions throughout life, and how chemistry directly affects our world. It segues into this by introducing the acid that certain ants produce to effectively do "gardening" by killing off any intruding plant life.
It goes on to describe molecular structure, how atoms and elements bond, focusing on the emergent properties of water. Water has many interesting qualities due to the weak hydrogen bonds, including cohesion and adhesion. Then it ends with my favorite part- the ecological practices! From dying coral reefs to finding life on Mars, ecological biology rocks my world.
http://www.youtube.com/watch?v=qmgE0w6E6ZI
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