Atomic structure

• What particles make up the nucleus of an atom?

  Protons and neutrons
• What is the overall charge of the nucleus?


  Positive charge
• In a neutral atom, what is the relationship between the number of electrons and protons?


  The number of electrons is equal to the number of protons
• What is the relative charge of a proton?


  +1
• What is the relative charge of a neutron?


  0
• What is the relative mass of a proton?


  1
• What is the relative mass of a neutron?


  1
• What is the relative mass of an electron?


  1/1840
• 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 before the next one can hold any electrons
• What does the mass number (A) represent?


  The sum of protons and neutrons in an atom
• If an atom has an atomic number of 7 and a mass number of 14, how many neutrons does it have?


  7 neutrons
• What is relative atomic mass (Ar)?


  The mean mass of an atom of an element divided by one twelfth of the mean mass of an atom of the carbon-12 isotope

  
• What do isotopes have in common?


  They have the same atomic number but different numbers of neutrons
• What is an ion?


  An atom that has lost or gained electrons and has an overall charge
• What is mass spectrometry used for?


  To identify different isotopes and find the overall relative atomic mass of an element
• What does Time of Flight (TOF) Mass Spectrometry measure?


  The time it takes for ions of each isotope to reach a detector
• What are the steps involved in Time of Flight (TOF) Mass Spectrometry?


  1. Ionisation: Sample is vapourised and ionised to form +1 charged ions.
  2. Acceleration: Positively charged ions are accelerated towards a negatively charged plate.
  3. Ion Drift: Ions are deflected by a magnetic field into a curved path.
  4. Detection: Ions hit the detection plate, gaining an electron and producing a flow of charge.
  5. Analysis: Current values and flight times are used to produce a spectra print-out.
• What happens during the ionisation process in mass spectrometry?


  A sample is vapourised and ionised, leaving +1 charged ions in the chamber
• What occurs during the detection phase of mass spectrometry?


  Positive ions hit the detection plate, gain an electron, and produce a flow of charge
• Why do isotopes of chlorine produce different combinations in mass spectrometry?


  Because one isotope is more common than the other
• What are the types of electron orbitals?


  s, p, d, and f orbitals
• How many electrons can an s-orbital hold?


  2 electrons
• How many electrons can a p-orbital hold?


  6 electrons
• How many electrons can a d-orbital hold?


  10 electrons
• In what order are the orbitals filled?


  From s to d, with each orbital filled before the next one is used
• What is the electron configuration for sodium (Na) with 11 electrons?


  Na = 1s²2s²2p⁶3s¹
• What are the three rules for writing electron configurations?


  1. The lowest energy orbital is filled first.
  2. Electrons with the same spin fill an orbital first before pairing begins.
  3. No single orbital holds more than 2 electrons.
• What is ionisation energy?


  The minimum energy required to remove one mole of electrons from one mole of atoms in a gaseous state
• How does first ionisation energy change along a period in the Periodic Table?


  It increases due to a decreasing atomic radius and greater electrostatic forces of attraction
• How does first ionisation energy change down a group in the Periodic Table?


  It decreases due to an increasing atomic radius and shielding