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Chemistry - 3.1 The periodic table and energy > Ionisation Energy > Flashcards

Flashcards in Ionisation Energy Deck (12)
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When does Ionisation energy occur

When atoms lose or gain electrons


What is ionisation energy

the energy needed to form positive ions


Definition of the first ionisation energy

the first ionisation energy of an element is the energy required to remove one electron from each atom in one mole of the gaseous element to form one mole of gaseous 1+ions


Describe Atomic radius

The larger the atomic radius, the smaller is the nuclear attraction experienced by the outer electrons. This is because the positive charge of the nucleus is further away from the outermost electron.


Describe Nuclear charge

The higher the nuclear charge, more protons, the larger is the attractive force on the there outer electrons


What is the electrons shielding

its when the inner shells of electrons repel


Describe electron shielding

the more inner shells there are, the larger is the shielding effect and the smaller is the nuclear attraction experienced by the outer electrons


Why is each succesive ionisation energy higher than the one before?

> As each electrons is removed, there is less repulsion between the remaining electrons and each shell will be drawn in slightly closer to the nucleus
>The positive nuclear charge will outweigh the negative charge every time an electron is removed
> As the distance of each electron from the nucleus decreases slightly, the nuclear charge attraction increases therefore more energy is needed to remove each successive electron.


Describe ionisation energy across a period

The first ionisation energy increases:
> Nuclear charge increases across a period,
> Electron shielding remains the same
> Atomic radius decreases which results in an increase in clear attraction on the outer electron


Describe Ionisation energy down a group

The first ionisation energy decreases:
> Electron shielding increases
> Atomic radius increases which causes a
> Decrease on nuclear attraction


Describe ionisation energy between group 2 and 13 element (Be --> B)

decreases This is because group 13 outermost electron is in a p orbital and group 2 element have theirs in s orbital and p have higher energy than s as they are further away from the nuclei so electrons are easier to be removes.


Describe ionisation energy between group 15 and 15 element (N --> O, P --> S)

as you move electrons are found in a p-orbitals where they only contain a single electron however in group 16 the outermost electrons is spin paired which experience some repulsion