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Chapter 2 - Coggle Diagram

- - - - required in very small amounts
        
        Flouride
        
        strengthen teeth and bones, prevent cavities
        
        Iron
        
        prevent anemia
        
        Too much iron can damage organs
        
        Iodine
        
        prevent thyroid enlargement
    - - same element; same number of protons but different number of neutrons
      - Radioactive Isotopes
        
        Unstable isotopes from imbalance of protons &
        neutrons
        
        Can be natural or
        man-made
        
        Decay, emitting radiation, until more stable
        
        There are different types of decay
        
        Alpha decay: nucleus emits 2 protons + 2
        neutrons (alpha particle)
        
        Example: Fluorine-18 (¹⁸F): tracer in PET scans
        
        Radioactive isotopes give off energy that can
        damage cells & organs if exposure is too high
  - - - Neutrons
        
        neutral, nucleus
      - Electrons
        
        negative,
        surrounding nucleus
      - Protons
        
        positive, nucleus
    - - Mass number
        
        number of protons + neutrons
      - Atomic mass
        
        average mass shown on the
        periodic table
      - Atomic number
        
        number of protons
        
        Every atom of an element has the same number
        of protons
        
        In a neutral atom, the number of protons also
        equals the number of electrons
      - Electron shells
        
        Valence shells
        
        Outermost electrons
        
        Determine chemical behavior
        
        Determine bonding
      - Structural formula
        
        Shows bonds with lines
      - Molecular formula
        
        Shows only the number of atoms
  - - - Equation is balanced if same number of each
        type of atom occurs on both sides of the arrow
- - - - Polar covalent bonds
        
        Electrons are shared unequally between atoms
      - weak attraction between a hydrogen atom and another slightly electronegative atom
  - - - Good solvent, water is polar; can form hydrogen bonds with other molecules
      - Hydrophobic; 'water fearing', does not mix with water
      - Hydrophilic; 'water-loving', mixes well with water
    - - Cohesion
        
        water sticks to itself because of hydrogen bonds
      - Adhesion
        
        water sticks to other surfaces that are polar
    - - water molecules at surface form stronger bonds
    - - water heats up and cools down slowly
      - hydrogen bonds hold the molecule together tightly
    - - requires a lot of heat to turn water into vapor as hydrogen bonds need to be broken
        
        cooling effect; heat is carried away as water evaporates
    - - ice is less dense than water
        
        Floating ice insulates the water below, helping
        aquatic life survive in winter
      - hydrogen bonds between ice molecules allow them to be spaced further apart
  - - - Have a high concentration of H⁺ ions (protons) when mixed with water
      - The more H⁺, the stronger the acid
    - - Bases have high concentration off OH⁻ ions
        (hydroxide) when mixed with water
      - The more OH⁻, the stronger the base.
  - - - Buffers: chemicals that keep pH
        stable by soaking up extra H⁺ or OH⁻ ions
        
        Minimizes changes in pH
        • Usually weak acid + weak base
- - - - Transfer electrons
      - Form ions
      - Opposite charges attarct
      - Ion: atom or molecule with an electrical charge
        from gain/loss of 1+ electrons
    - - Atom share electrons
      - Form molecules