# Ionisation Energy

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• Created by: Zammi10
• Created on: 17-09-16 18:39
Define the ionisation energy...
Ioinisation energy is a measure of the ease in which atoms llose electrons and become positive ions
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What is the first ionisation energy?
the energy per mole needed to remove an electrom from gaseous atoms
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School's definition?
The first ionisation energy of an element is the energy required to remove one mol of electrons from one mole of atoms of the element in the gaseous state to form gaseous ions.
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what type of atoms?
gaseous atoms
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General formula for first ionisation energy>
X (g) --> X+ (g) + e-
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What is the second ionisation energy?
The energy per mole needed to remove an electron from gaseous atoms with a single positive charge
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General formula for second ionisation energy>
X+ (g) --> X2+ (g) + e-
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What are the first and second ionsisation energies 2 of?
a series of successive inisation energies until all the electrons have been removed
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What is energy usually quotedi n=in?
kJ/mol
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Why is energy required to remove an electron>
It's required in order to overcome the electrostatic force between an electron and the positively charged nucleus.
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what is the first AND second ionisation energy of Magnesium?
Mg--> Mg2+ 2e-
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Ionisatio energies always have what sort of value?
endothermic and positive values
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What do the ionisation energies of different electrons in an element prove?
It provides evidence for the presence of quantum shells. This is as on the graph, big 'jumps' are seen- these are where electrons are emoved from the next energy level- this is as these electrons are now closer to the nucleus, therefore more energy
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continued
is needed to remove them.
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What happens to the first ionisation energy as you go down a group?
It decreases-This is because the electron to be removed from the outer energy level is increasingly distant from the nucleus, as a result of the atoms getting bigger. The attraction of the nucleus for the electron becomes less-easier to pull away.
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Why else does this happen?
Because the amount of shielding increases
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## Other cards in this set

### Card 2

#### Front

What is the first ionisation energy?

#### Back

the energy per mole needed to remove an electrom from gaseous atoms

### Card 3

#### Front

School's definition?

### Card 4

#### Front

what type of atoms?

### Card 5

#### Front

General formula for first ionisation energy>