lesson 2

• What are the main atomic structure concepts mentioned in the study material?


  Valency, valence electrons, electronegativity, octet rule
• What are bioelements?


  Chemical elements present in living organisms
• What are the two categories of mineral elements?

  Bulk elements and trace elements
• Which bioelements are primarily found in the oral cavity?


  C, H, O, N
• What distinguishes covalent bonds from non-covalent bonds?


  Covalent bonds involve sharing electrons, while non-covalent bonds do not
• What are the two types of covalent bonds?


  Polar and non-polar covalent bonds
• What are the types of non-covalent bonds mentioned?


  Ionic and metallic bonds
• What is the primary organic element discussed in the study material?

  Carbon
• What are the characteristics of carbon?


  Carbon can form four covalent bonds and has a unique ability to form long chains
• What are functional groups in organic chemistry?


  Specific groups of atoms that determine the characteristics and reactions of organic compounds
• What are the types of biomolecules?


  • Organic biomolecules: Carbohydrates, Lipids, Proteins, Nucleotides
  • Inorganic biomolecules: Water, Salts, CO2
• What types of interactions occur within and between biomolecules?

  Electrostatic, hydrogen bonding, van der Waals forces, hydrophobic interactions
• What is the nucleus of an atom composed of?


  Protons and neutrons
• What does the atomic number represent?


  The number of protons in an element's atomic nucleus
• What is atomic weight or mass?


  The sum of the number of protons and neutrons in an element's atomic nucleus
• What are isotopes?


  Elements possessing different numbers of neutrons
• What is the significance of radioactive isotopes?


  They are used to follow biochemical reactions and date specimens
• What is electronic distribution in atomic structure?


  The way electrons are distributed within the atom cortex
• What is the valence level in atomic structure?


  The most external layer occupied by electrons
• What is the Moeller Diagram used for?


  To represent the distribution and occupation of orbitals by electrons
• What do Lewis diagrams represent?


  Paired and unpaired valence electrons in an atom
• What is electronegativity?


  The tendency of an atom to attract electrons towards itself in a molecule
• How does electronegativity change in the periodic table?


  It increases from the left bottom side to the right upper corner
• What is the octet rule?


  Atoms seek stability by completing their outer electron shells
• Which elements account for 99% of organic matter?


  C, H, O, N

  
• What are primary bioelements?


  Elements that account for 99% of cellular mass
• What are secondary bioelements?


  Elements that appear in all living organisms and are essential
• What are oligoelements?


  Elements that account for less than 0.1% and are essential for life
• What role do calcium, phosphate, and magnesium ions play in saliva?


  They are responsible for enamel maturation and remineralization
• What is the effect of fluoride on dental health?


  Fluoride prevents caries formation and enhances enamel hardness
• What happens with excessive fluoride intake during tooth development?


  It can lead to mottled enamel or enamel fluorosis
• What is the difference between polar and non-polar covalent bonds?


  Polar bonds have asymmetrical electron distribution, while non-polar bonds have equal distribution
• What determines the type of chemical bond between two elements?

  The electronegativity difference between the atoms
• What is the significance of covalent bonds in biological molecules?


  Covalent bonds define the structure of molecules important for life
• How are covalent bonds formed?


  By sharing electrons between non-metal atoms
• Why are covalent bonds stronger than non-covalent bonds?


  Because they require considerable energy to break
• What is a polar molecule?


  A molecule with an electric dipole due to unequal electron sharing
• What is a non-polar molecule?


  A molecule with equal electron sharing between atoms
• What is the example of a non-polar molecule given in the study material?


  CH4
• What is the example of a polar molecule given in the study material?


  H2O