Atomic Structure and Nanoparticles (1.1 and 1.4)

• What is the smallest particle of an element that can exist on its own?

  Atom
• Who discovered the electron in 1897?

  J.J Thomson
• What does the plum pudding model describe?

  A sphere of positive charge with electrons
• What did Ernest Rutherford discover in 1909?

  Proton
• What did Rutherford discover in 1911?

  Nucleus
• Who proved the existence of the neutron in 1932?

  James Chadwick
• What does the nucleus contain?

  Protons and neutrons
• What is the radius of an atom?

  0.1 nm (1x10^-10 m)
• How does the size of the nucleus compare to the size of the atom?

  Nucleus is less than 1/10,000 size of atom
• What is the size comparison of the nucleus to an atom likened to?

  Like a marble compared to a football stadium
• What is the size range of nanoparticles?

  1-100 nm
• How many atoms do nanoparticles typically contain?

  A few hundred atoms
• What is a key property of nanoparticles compared to bulk material?

  High surface area to volume ratio
• What are the benefits and risks of using nanoparticles in sunscreen?

  Benefits:

  • Better skin coverage
  • More effective against UV rays
  • Clear and colorless
  • Don't degrade in sunlight

  
  

  Risks:

  • Potential cell damage
  • May penetrate cell membranes
  • Toxic inside the body
  • Harmful environmental effects
• What are the three subatomic particles?

  Protons, neutrons, electrons
• What is a cation?

  A positive ion
• What happens to electrons in a cation?

  Electrons are lost
• What is an anion?

  A negative ion
• What happens to electrons in an anion?

  Electrons are gained
• How does the name of an anion change?

  Ends in -ide
• What is the electronic configuration of an ion?

  Same as nearest noble gas
• What are isotopes?

  Atoms with same protons, different neutrons
• How do isotopes differ physically?

  They have different mass numbers
• What is relative atomic mass (RAM)?

  Mass compared to Carbon-12 isotope
• How is RAM calculated?

  Weighted mean of mass numbers
• What is the formula for calculating RAM with two isotopes?

  RAM = (mass 1 x abundance) + (mass 2 x abundance)
• What does the total abundance refer to in RAM calculation?

  Sum of all isotopes' abundances
• What is the significance of the atomic number?

  Total number of protons in nucleus
• What is the mass number?

  Total number of protons and neutrons
• How is electronic configuration divided?

  Into cells or shells
• What is the outer shell in atomic structure?

  Last occupied electron shell
• What does the group number indicate in atomic structure?

  Number of electrons in outer shell
• What does the period number indicate in atomic structure?

  Number of occupied electron shells
• What is an ion?

  A charged particle from electron loss or gain
• What happens to an atom when it loses electrons?

  It becomes a cation
• What happens to an atom when it gains electrons?

  It becomes an anion
• What is the relationship between isotopes and chemical properties?

  Isotopes have same chemical properties
• What is a characteristic of isotopes in terms of density?

  They may be denser
• What does the term "mass number" refer to?

  Sum of protons and neutrons
• How does RAM account for isotopes?

  It considers % abundance of isotopes