DEFINITIONS

• What is the second stage of TOF spectrometry?

  Acceleration of positively charged ions
• What is an atom?

  The smallest part of an element
• What is the atomic nucleus composed of?

  Protons and neutrons
• What does the atomic number represent?

  The number of protons in the nucleus
• What is the relative mass of an electron?

  1/2000
• What does electron configuration describe?

  The distribution of electrons in orbitals
• What is electron impact ionisation?

  Ionisation method using high energy electrons
• How does electrospray ionisation work?

  Sample is dissolved and gains H​+​ ions
• What is first ionisation energy?

  Energy to remove 1 mole of electrons
• What happens during ion detection in TOF spectrometry?

  A mass spectrum is produced
• What occurs during ion drift in TOF spectrometry?

  Ions drift through a region with no electric field
• What is ionisation in TOF spectrometry?

  The first stage of TOF spectrometry
• What is an isotope?

  Atoms with the same protons, different neutrons
• What does mass number represent?

  Total number of protons and neutrons
• What does a mass spectrometer provide information about?

  Relative isotopic mass and abundance
• How is mass spectrometry used?

  To identify elements and determine molecular mass
• What is a neutron?

  Neutral subatomic particle in the nucleus
• What is nuclear charge?

  Total charge of all protons in the nucleus
• What is a proton?

  Positively charged particle in the nucleus
• What is second ionisation energy?

  Energy to remove 1 mole from 1+ ions
• What are sub-shells in electron shells?

  Divisions with different energy levels
• What types of sub-shells exist?

  s, p, d, and f
• What is a Time of Flight (TOF) spectrometer?

  A method to determine mass-to-charge ratio
• What are the four stages of TOF spectrometry?

  Ionisation, acceleration, ion drift, detection
• What is atom economy?

  Measure of useful products from starting materials
• What is Avogadro’s constant?

  Number of units in one mole of substance
• What does concentration measure?

  Amount of substance per unit volume
• What is an empirical formula?

  Smallest whole number ratio of atoms
• What is a limiting reactant?

  The reactant completely used up in a reaction
• What is a mole?

  Mass containing same units as 12 g of carbon-12
• What is a molecular formula?

  Actual ratio of atoms in a compound
• What does percentage by mass represent?

  Concentration of an element in a compound
• What is percentage yield?

  Actual yield compared to theoretical yield

  
• What is relative atomic mass?

  Average mass compared to carbon-12
• What is relative molecular mass?

  Average mass of one molecule compared to carbon-12
• What is a co-ordinate bond?

  Shared pair of electrons from one atom
• What is a covalent bond?

  Shared pair of electrons between non-metals
• What is a dipole?

  Difference in charge due to electronegativity
• What is electron pair repulsion?

  Repulsion between negatively charged electron pairs
• What is electronegativity?

  Power to attract electron density in a bond