- Created by: April_Higgin
- Created on: 15-05-14 10:13
Mass numbers and isotopes
Mass number- the number of protons and neutrons in the nucleus of one atom of an element.
Relative atomic mass- the average mass of one atom of an element/one twelfth the mass of one atom of carbon-12.
Atomic number- the number of protons in the nucleus of an atom.
Isotope: atoms of the same element but with different mass numbers.
Ionisation- The gaseous atoms are ionised by knocking one or more electrons off using an electron gun to give a positive ion.
Acceleration-The positive ions are accelerated by an electric field and focused by passing through a series of slits.
Deflection- The fast moving beam of electrons are deflected by a strong electromagnet. The magnitude of deflection depends on the mass:charge ratio. If m/z is small, the deflection is large.
Detection- The ion hits the detector and accepts an electron from the detector which creates a small current. This current is amplified and produces a signal on a computer.
First Ionisation Energy
First ionisation energy- The enthalpy change for the removal of one mole of electrons from one mole of atoms of an element in the gas phase.