Boardworks AS Chemistry Atomic Structure Teacher notes acceleration – The stage of mass spectrometry during which the movement of the ions of the sample is speeded up using a series of negatively-charged plates. atomic number – The number of protons in the nucleus of an atom of an element. Represented by the symbol Z. Also called the proton number. deflection – The stage of mass spectrometry during which the beam of ions is bent by a particular amount, depending on its mass-to-charge ratio. This is achieved using an electromagnet. detection – The stage of mass spectrometry during which the ions strike a collector plate, producing a mass spectrum for analysis. diatomic – A molecule consisting of two atoms. electromagnet – The part of a mass spectrometer responsible for the deflection of the beam of ions. It consists of a wire coiled around an iron core, which is magnetized when electric current flows through the wire. electron – A negatively-charged particle found in energy levels around the nucleus of an atom. The mass of an electron is 1/1840 the mass of a proton or neutron. electron gun – The part of a mass spectrometer responsible for the ionization of the sample. It works by bombarding the sample atoms with high-energy electrons. ionization – The stage of mass spectrometry during which the atoms of the sample lose electrons to become positive ions. isotopes – Atoms of the same element with different numbers of neutrons. mass number – The number of protons plus the number of neutrons in an atom. Represented by the symbol A. mass spectrometry – An accurate instrumental technique that can be used to determine the relative isotopic mass and the relative abundance for each isotope of an element in a sample. This can be used to identify the sample. mass-to-charge ratio – The mass divided by the charge of an ion. Often called the m/z value. neutron – A neutral particle found in the nucleus of an atom. Has a relative mass of 1. proton – A positively-charged particle found in the nucleus of an atom. Has a relative mass of 1. proton number – The number of protons in the nucleus of an atom of an element. Represented by the symbol Z. Also called the atomic number. relative atomic mass – The average mass of an atom of an element, taking into account the natural abundances of its isotopes, relative to 1/12 the mass of an atom of carbon-12. Represented by the symbol A r . relative isotopic mass – The mass of an atom of a particular isotope of an element relative to 1/12 the mass of an atom of carbon-12. subatomic particles – The particles of which an atom consists, including protons, neutrons and electrons. vaporization – The stage of mass spectrometry during which the sample is heated to form a gas.
