Pmt

• What has evolved over time in atomic structure?

  The model for atomic structure
• What does the current model of the atom consist of?

  A small, dense nucleus and orbiting electrons

  
• What experiment discovered the atomic structure model?

  The Rutherford scattering experiment
• What particles make up the nucleus of an atom?

  Protons and neutrons
• What charge does the nucleus of an atom have?

  Overall positive charge
• In a neutral atom, what is equal to the number of protons?

  The number of electrons
• What are the relative charges and masses of protons, neutrons, and electrons?

  • Proton: Charge +1, Mass 1
  • Neutron: Charge 0, Mass 1
  • Electron: Charge -1, Mass 1/1840
• How is the maximum number of orbiting electrons in a shell calculated?

  Using the formula $2n^2$
• How many electrons can shell 2 hold?

  8 electrons
• What must happen before the next electron shell can hold electrons?

  Each electron shell must fill
• What does the mass number (A) represent?

  The sum of protons and neutrons
• What does the atomic number (Z) represent?

  The number of protons in an atom
• How do you calculate the number of neutrons in a nitrogen atom?

  Mass number - Atomic number
• What is the neutron number in a nitrogen atom with atomic number 7 and mass number 14?

  7 neutrons

  
• What happens when an atom loses or gains electrons?

  It forms an ion with an overall charge
• How many electrons does a lithium ion (Li⁺) have if lithium has 3 electrons?

  2 electrons

  
• What are isotopes?

  Atoms of the same element with different neutrons
• How do neutral atoms of isotopes react chemically?

  They react the same way chemically
• What is the difference in physical properties of isotopes due to?

  Different mass numbers
• What are examples of hydrogen isotopes?

  • Hydrogen: 1 proton, 1 neutron
  • Deuterium: 1 proton, 2 neutrons
  • Tritium: 1 proton, 3 neutrons
• What is relative atomic mass (Ar)?

  The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

  
• What does relative atomic mass take into account?

  The relative abundances of isotopes

  
• What is relative isotopic mass?

  The isotopic mass relative to carbon-12
• What is relative molecular mass (Mr)?

  The weighted mean mass of a molecule

  
• How is relative molecular mass calculated?

  By adding Ar values of component elements

  
• What is relative formula mass?

  Similar to Mr for giant structures
• What is mass spectrometry used for?

  To identify different isotopes
• What does Time of Flight (TOF) mass spectrometry record?

  The time for ions to reach a detector
• What do spectra produced in mass spectrometry show?

  Each isotope present and their abundances
• How is relative atomic mass (Ar) calculated from spectra?

  By multiplying m/z values by abundances

  
• What is the characteristic pattern in chlorine spectra?

  A 3:1 ratio for Cl⁺ ions

  
• What isotopes are present in chlorine?

  Chlorine-35 and Chlorine-37
• What is ionic bonding?

  Bonding between a metal and a nonmetal
• What happens to electrons during ionic bonding?

  Electrons are transferred from metal to non-metal
• What are binary compounds?

  • Compounds containing only 2 elements
  • Named by putting the metal first
  • Ending of the second element changed to -ide
• What is the ionic formula for calcium chloride?

  CaCl₂
• What are key polyatomic ions to know?

  • NO₃⁻ = nitrate ion
  • SO₄²⁻ = sulfate ion
  • CO₃²⁻ = carbonate ion
  • OH⁻ = hydroxide ion
  • NH₄⁺ = ammonium ion
• How can an element's ionic charge be predicted?

  From its position in the periodic table
• What charge do Group 1 metals form?

  1+ ions
• What charge do Group 2 metals form?

  2+ ions