Ionisation Energy Flashcards
Define ionisation
The conversion of an atom to an ion
Define the first ionisation energy
The energy needed to remove one mole of electrons from one mole of a gaseous element to form one mole of gaseous positive ions
What are the 3 factors that effect ionisation energy
Nuclear charge, distance of valence electron and shielding
What is nuclear charge
The attraction on the electrons surrounding the nucleus from the positive protons located within the nucleus of an atom or ion
What does nuclear charge depend on
Number of protons (the more protons the greater the nuclear charge)
What is the relationship between nuclear charge and ionisation energy
The greater the nuclear charge the greater the ionisation energy
how does the distance of valence electrons impact IE
as the atomic radi increases, the distance increases and so the attractions between the nucleus and the valence electrons decrease and so this tends to decrease IE
What is the shielding effects
It is the lowering of the nucleus pull/attraction on the electron furthest away from the nucleus due to electrons in closer energy shells
Why does the nucleus attract electrons
Because the nucleus has a positive charge whilst an electron has a negative charge and opposite charges attract
When is always needed to remove electrons
An input of energy
What is the general ionisation energy reaction
X(g) —> X+(g) + e-
How can you identify which ionisation energy the equation is
With whatever charge the ion created has
What is a successive ionisation energy
The 2nd 3rd 4th ect… ionisation energys
What happens the atomic radi when electrons are removed
Decreases
what do scientists use to study ionisation energies
Spectroscope
how is a spectroscope used to study ionisation energy
the light (electromagnetic waves) that are let out by atoms when they are heated, is studied
what does a spectroscope physically show
bright lines on a black background
what happens to atoms when heated
they get energy so the electrons jump to a higher energy level
what is a line emission spectrum
where each line in the spectrum arises from the energy released as the electrons drop back from a a higher energy level to a lower level
why is each elements spectrum different
bveacuse each element has its own characteristic set of lines as they are unique to themselves
what does the line emission spectrum provide evidence for
the existence of quantum shells in an atom
what doe successive ionisation energies provide evidence for
the existence of groups and subshells
how does electron shielding work
the inner electron exerts a repulsion force on outer shell electrons and this reduces attraction to the nucleus
what is the relationship between no of shells and shielding effect
the greater the no of shells, the greater the increase in shielding effect
what is the relationship between shielding effect and IE
the higher the shielding effect, the lower the ionisation energy because there is a reduced attraction to the nucleus
does it get more or less difficult to remove successive electrons from an atom?
more
as the number of IE increases, the difficulty in removing electrons….
also increases
what does successive IEs depend on
electronic configuration of the atom
