Ionisation Energies Flashcards
How does the protons of an atom effect the amount of energy required to remove its electrons?
The more protons in the nucleus of an atom, the more attracted the electrons are to the nucleus therefore the harder it is to remove the electrons.
What is the number of protons in the nucleus referred to as?
The nuclear charge.
What is shielding?
When the inner shell electrons cancel out one unit of charge from the nucleus’ protons.
What is the first ionisation energy of an element?
The first ionisation energy of an element is the energy required to remove one electron from one mole of free gaseous atoms of that element.
What is the effective nuclear charge?
The positive charge of an atom that the outermost electrons feel when all inner shell electrons have cancelled out the nuclear charge.
What is the second ionisation energy of an atom?
The second ionisation energy of an atom is the energy required to remove one electron from one mole of free gaseous unipositive ions.
What is the third ionisation energy of an atom?
The third ionisation energy of an atom is the energy required to remove one electron from one mole of bipositive ions.
Explain the general upward trend of ionisation energy of period 3 elements.
As you go along the period there are more protons in the nucleus and the same shielding.
Explain the dip in ionisation energy at aluminium on the graph.
Increased shielding in aluminium means that the outermost electron slightly further from the nucleus. Therefore it is easier to remove and requires less energy.
Explain the dip in ionisation energy at sulphur.
Electrons experience spin-pair repulsion for the first time. They repel each other which means they are easier to remove than expected.
