Atomic Structure (continued)

Atomic Structure (continued)

1. How can you determine the Mr, relative molecular mass, of a covalent compound from a mass spectra?

   • The Mr is equal to the m/z value of the peak with the greatest m/z value

2. Electron Arrangement

   • There are 4 types of orbital
     • S (spherical)
       • Max of 2 electrons
     • P (dumb-bell)
       • Max of 6
     • D
       • Max of 10
     • F
       • Max of 14
   • Ionisation energy
     • First ionisation energy is the energy needed to remove one electron off a gaseous atom
     • Why is the 2nd ionisation energy is greater than the 1st ?
       • because the ion has a smaller radius ad less shielding than the atom
     • Ionisation energy DECREASES DOWN a GROUP
       • because there is an increasing atomic radius and greater shielding, so the outer electron is attracted less strongly to the nucleus
     • Why is the 2nd ionisation energy MUCH greater than the 1st?
       • because the 2nd electron is removed from the ....energy level, which is closer to the nucleus and shielded less, so the electron is attracted more strongly to the nucleus
     • Ionisation energy INCREASES across a PERIOD
       • because there is increased nuclear charge and similar shielding, so the outer electron is much more strongly attacted to the nucleus
     • Group 3 LESS THAN group 2
       • group 3's outer electron is in a higher energy ..p orbital whereas group 2's outer electron is in a ..s
     • Group 6 LESS THAN group 5
       • Group 6 has a pair of electrons in the same..p orbital which repel