Ionisation energies Flashcards
What is first ionisation energy?
The energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions
What do you need to remember when you write an ionisation energy equation?
All reactants and products in gaseous form
1 mole of atoms
The charge on the product is the same as the number ionisation energy it is
What are the three factors that affect ionisation energy?
Nuclear charge
Distance from nucleus
Shielding
How does nuclear charge affect ionisation energy?
The most protons, the stronger the attraction of the electrons to the nucleus so they are harder to lose and the ionisation energy becomes higher
How does distance from the nucleus affect ionisation energy?
An electron closer to the nucleus will be more strongly attracted than a one further away so their ionisation energy will be higher
How does shielding affect ionisation energy?
The more electron shells, the more shielding which means the electrons are less attracted to the nucleus and therefore the ionisation energy will be lower
What is second ionisation energy?
The energy needed to remove an electron from each ion in 1 mole of gaseous +1 ions to form one mole of gaseous 2+ ions
Why is the second ionisation energy higher than the first?
An electron is being removed from a positive ion which will require more energy than if it was just an atom
What is successive ionisation energy?
Removing all electrons and just leave the nucleus
Why does ionisation energy decrease as you move down the group?
- there is an extra shell every time you go down
- provides more shielding
- outer electrons are less strongly attracted to the nucleus
- lower ionisation energy
What is the general trend in ionisation energies in period 3?
Generally increase
What are the two dips in ionisation energy along period 3?
Aluminium
Sulfur
