chemia

    Cards (93)

    • What is the smallest part of an element that can exist?
      An atom
    • What does the chemical symbol Na represent?
      An atom of sodium
    • What happens during a chemical reaction?
      Formation of one or more new substances
    • What is a compound?
      Two or more elements chemically combined
    • What is the formula for a compound containing 1 atom of hydrogen and 1 atom of chlorine?
      HCl
    • How can compounds be separated into elements?
      By chemical reactions
    • What is a mixture?
      Two or more elements or compounds not chemically combined
    • How can mixtures be separated?
      By physical processes like filtration
    • What was the first model of the atom?
      Tiny spheres that could not be divided
    • What did the plum pudding model propose?
      Atom is a ball of positive charge with electrons embedded
    • What did the alpha particle scattering experiment conclude?
      Mass of the atom is concentrated at the nucleus
    • Who suggested that electrons orbit the nucleus at specific distances?
      Neil Bohr
    • What did James Chadwick discover?
      Existence of neutrons
    • What is the atomic number of an element?
      Number of protons in an atom
    • What is the relative charge of a proton?
      +1
    • What is the relative charge of a neutron?
      0
    • What is the relative charge of an electron?
      -1
    • Why does an atom have an overall charge of 0?
      Number of protons equals number of electrons
    • What is the approximate radius of an atom?
      0.1 nm
    • What is the mass number of an atom?
      Sum of protons and neutrons
    • What are isotopes?
      Atoms of the same element with different neutrons
    • What is relative atomic mass?
      Average value considering isotope abundance
    • Calculate the relative atomic mass of carbon with isotopes carbon-12 (80%) and carbon-14 (20%).
      12.4
    • Where do electrons occupy in an atom?
      Lowest available energy levels
    • What is the electronic structure of sodium?
      2,8,1
    • What are the key differences between compounds and mixtures?
      • Compounds: chemically combined, fixed proportions, separated by chemical reactions
      • Mixtures: not chemically combined, variable proportions, separated by physical processes
    • What are the key findings from the alpha particle scattering experiment?
      • Mass of atom concentrated at nucleus
      • Nucleus is positively charged
      • Most alpha particles passed through, some deflected
    • What are the properties of subatomic particles?
      • Proton: charge +1, mass 1
      • Neutron: charge 0, mass 1
      • Electron: charge -1, very small mass
    • What are the steps to calculate relative atomic mass?
      1. Multiply each isotope's mass by its abundance
      2. Sum the results
      3. Divide by 100
    • How do electrons arrange themselves in an atom?
      • Occupy lowest available energy levels (shells)
      • Shells closest to nucleus filled first
      • Electronic structure indicates electrons per shell
    • What is the size range of nanoparticles?
      1-100 nanometers
    • How many atoms do nanoparticles typically contain?
      A few hundred atoms
    • Why do nanoparticles have different properties compared to bulk materials?
      High surface area to volume ratio
    • What is the diameter range of fine particles (PM2.5)?
      100-2500 nm
    • What is the diameter range of coarse particles (PM10)?
      1 x 10⁻⁵ m to 2.5 x 10⁻⁵ m
    • What happens to the surface area to volume ratio when the size of a particle decreases by a factor of 10?
      It increases by a factor of 10
    • Why would nanoparticles make good catalysts?
      High surface area to volume ratio
    • What is one use of nanoparticles in cosmetics?
      Sun tan cream
    • What is one use of nanoparticles in building materials?
      Stronger, lighter materials
    • Why are nanoparticles used in lubricant coatings?
      They reduce friction
    See similar decks