Topic 1 Flashcards
What is meant by the term periodicity?
Periodicity is the regular repeating pattern of atomic, physical and chemical properties with increasing atomic number
Definition of relative atomic mass
The weighted mean mass of an atom of an element compared to 1/12 th of the mass of an atom of carbon-12
Definition of ionisation energy
The minimum amount of energy required to remove 1 mole of electrons from 1 mole of atoms in gaseous state
General equation for first ionisation energy
A(g) –> A+(g) + e-
Why is ionisation energy endothermic?
Requires energy it is bond breaking
Successive ionisation energies
The removal of one or more electrons from the same atom
Why does ionisation energy decrease going down the group?
- more shielding going down further electron repulsion from outermost electron to nucleus
-nuclear charge increase in protons leads to a stronger force of electrostatic attraction between nucleus and outermost electron
-atomic size means further distance between valent electron and nucleus
What is meant by the M+1 peak?
refers to the molecular ion peak
indicates presence of Carbon-13 isotope
the same as the mr of the molecule
Definition of second ionisation energy
The energy needed to remove 1 electron from each ion in one mole of gaseous 1+ ions to form 1 mole of 2+ gaseous ions
Trend in successive ionisation energies within a sub shell
There is an increase this is due to electrons are being removed from an increasingly positive ion- less repulsion.
Trend in atomic radius
Atomic radius decreases along a period
Increases down a group
Drop between group 5 and 6 in terms of ionisation energies
In group 5 one electron is being removed from a singly filled orbital
In group 6 one electron is being removed from a complete orbital- more electron repulsion easier to remove
Drop between group 2 and 3
In group 2, electrons are located in the 3s orbital and in group 2 located on the 3p orbital which is further located from nucleus meaning an easier removal of electrons
