Ionisation energies Flashcards
1
Q
First Ionisation energy
A
-energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions.
2
Q
Energy put in to ionise an atom or molecule
A
-endothermic process
3
Q
Factors affecting ionisation energy
A
- nuclear charge
- electron shell
- sheilding
4
Q
nuclear charge
A
- more protons in nucleus
- more positively charged nucleus is and stronger attraction for electrons
5
Q
Electron shell
A
- attraction falls off very rapidly with distance
- electron in an electron shell close to nucleus will be much more strongly attracted than one in a shell further away
6
Q
Shielding
A
- as a number of electrons between outer electrons and nucleus increases outer electrons feel less attraction towards nuclear charge
- lessening of pull of the nucleus by inner shells of electrons called shielding
7
Q
high ionisation energy
A
- strong attraction between the electron and the nucleus
- more energy needed to overcome the attraction and remove the electron
8
Q
first ionisation energy decrease down a group
A
- easier to remove outer electron
- further done group so extra electron shells
- atomic radius is larger so outer electrons further away from nucleus so reduces attraction greatly
9
Q
Successive ionisation energy
A
- within each shell successive ionisation energies increase
- electrons being released from an increasingly positive ion
- less repulsion amongst remaining electrons so held more strongly by the nucleus
- big jumps in ionisation energy happen when a new shell is broken into so electrons being removed from shell close to nucleus