AS Level Chemistry Review Questions and Expert Solutions

Atomic number Number of protons in an element Mass number Number of protons and neutrons Ion Electrically charged particle formed by the loss/gain of electrons Relative masses of P,N and E 1,1, 1/2000 (respectively) Isotopes Atoms of the same element with different number of neutrons but same number of protons. What are steps of mass spectroscopy? Ionisation, Acceleration, Deflection, Detecting Ionisation A gaseous sample is bombarded with high energy electrons to create 1+ ions Acceleration They are accelerated through magnetic/electric field Deflection Ions are deflected through magnetic field according to mass (heavy - deflect least)(light - deflect most) Detection A calibrated detector records degree of deflection and interprets this into mass What does mass spectroscopy provide? Information about masses of particles inside machine and how often it's detected. What is shown on mass spectrum? Different isotopes relative abundance and molecular peak is furthest to right Molecular ion peak Peak corresponding to relative molecular mass of the compound (parent peak) Why are there sometimes line after the parent peak? They are a result of carbon 13 isotope and isn't considered when identifying a compound