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Chapter 2 The Chemical Context of Life - Coggle Diagram
Chapter 2 The Chemical
Context of Life
Elements & Compounds
Elements: C, H, O, N (96% of life)
Trace: Fe, I, Zn
Compounds: 2+ elements in fixed ratio (H₂O, NaCl)
Properties differ from elements
Atoms
Subatomic particles:
p⁺ (positive), n⁰ (neutral), e⁻ (negative)
Atomic # = protons
Mass # = p⁺ + n⁰
Isotopes: same element, diff neutrons
Radioactive → decay, used in research
Ions:
Cation (+) lost e⁻
Anion (–) gained e⁻
Electrons & Energy
Electron shells → energy levels
Valence electrons → outer shell, reactivity
Orbitals → 2 e⁻ each
Noble gases → full shell = stable
Electronegativity → attraction for e⁻
Chemical BondsChemical Bonds
Covalent: share e⁻
Nonpolar = equal (CH₄)
Polar = unequal (H₂O)
Ionic: transfer e⁻ (Na⁺Cl⁻)
Hydrogen: weak, between polar molecules
Van der Waals: weak attractions, close molecules
Chemical Reactions
Reactants → Products
Balance equations (same atoms both sides)
Rate affected by temp, conc., catalysts
Equilibrium: forward = reverse