The chemical context of life

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The chemical context of life
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Key concepts

• Matter consists of chemical elements in pure form
  and in combinations called compounds
• An elements properties depend on the structure
  of its atoms
• The formation and function of molecules depend on
  chemical bonding between atoms
• Chemical reactions make and break chemical bonds

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Key concepts

• Matter consists of chemical elements in pure form
  and in combinations called compounds
• An elements properties depend on the structure
  of its atoms
• The formation and function of molecules depend on
  chemical bonding between atoms
• Chemical reactions make and break chemical bonds

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The formation and function of molecules depend on
chemical bonding between atoms

• Different types of bonds
• Covalent bonds (strongest) - involves the sharing
  of electrons (i.e. H2)
• Electrons may be spread equally across the bond
  (non-polar bond)
• Electrons may not be spread equally across the
  bond (polar bond)

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The formation and function of molecules depend on
chemical bonding between atoms

• Different types of bonds
• Covalent bonds (strongest) - involves the sharing
  of electrons (i.e. H2)
• Electrons may be spread equally across the bond
  (non-polar bond)
• Electrons may not be spread equally across the
  bond (polar bond)

• Ionic bonds- Charge-charge interactions
• An interaction between a positive and negative
  charge
• Can form after one atoms strips a valence
  electron from another (ie. NaCl) forming a salt

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The formation and function of molecules depend on
chemical bonding between atoms
Ionic bond
Electron transfer forms ions
Cl Chlorine atom
Cl Chloride ion (an anion)
Na Sodium atom
Na Sodium ion (a cation)
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Which elements will most likely form an ionic
bond?

• a. Li and F
• b. C and O
• c. N and O
• d. Si and Cl
• e. H and H

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The formation and function of molecules depend on
chemical bonding between atoms

• Different types of bonds (weak)
• Hydrogen bonds- involve polar covalent bonds,
  form when a hydrogen atom is bonded to a more
  electronegative atom

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The formation and function of molecules depend on
chemical bonding between atoms

• Different types of bonds (weak)
• Hydrogen bonds- involve polar covalent bonds,
  form when a hydrogen atom is bonded to a more
  electronegative atom

This impacts the properties of water!
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The formation and function of molecules depend on
chemical bonding between atoms

• Different types of bonds (weak)
• Hydrogen bonds- involve polar covalent bonds,
  form when a hydrogen atom is bonded to a more
  electronegative atom
• Vander Waals interactions- involve non-polar
  covalent bonds, occur when an electron
  accumulation arises by chance

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The formation and function of molecules depend on
chemical bonding between atoms
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Chemical reactions make and break chemical bonds
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Chemical reactions make and break chemical bonds

• Chemical reaction- making a breaking of chemical
  bonds leading to changes in the composition of
  matter

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Chemical reactions make and break chemical bonds

• Chemical reaction- making a breaking of chemical
  bonds leading to changes in the composition of
  matter

6 CO2 6 H2O C6H12O6 6O2
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Chemical reactions make and break chemical bonds
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Key concepts

• Matter consists of chemical elements in pure form
  and in combinations called compounds
• An elements properties depend on the structure
  of its atoms
• The formation and function of molecules depend on
  chemical bonding between atoms
• Chemical reactions make and break chemical bonds