Electron configuration and periodicity Flashcards
define the first ionisation energy
the energy required to remove one electron from each atom in one mole of gaseous atoms
general equation for first ionisation energy
E(g) -> E+ (g) + e-
what is needed to remove an electron from an atom
energy
the larger the electrostatic attraction between the electron and the nucleus the
larger the ionisation energy
name three factors that affects ionisation energy
- number of protons
- the shielding
- the size of the atom
why does the number of protons affect ionisation energy
the more protons the greater nuclear charge of the nucleus, so a stronger attraction between valence electrons and the nucleus
why does shielding effect ionisation energy
inner electrons shield the outer electrons from the positive pull of the nucleus
how does the size of the atom effect ionisation energy
greater distance between the outer electron and positive nucleus,weaker attraction
what is the number of successive ionisation energies equal to
the charge on the ion formed `
how does ionisation energy change across a period
it increases
why does ionisation energy increase across a period
with a greater number of protons this increases the nuclear charge,
creating a greater pull to the nucleus meaning more energy is needed to remove the electrons
how does ionisation energy change down a group
it decreases
why does the ionisation energy decrease down a group
the shielding and the number of electron shells increase, this outweighs effects of the nuclear charge. so the nuclear attraction is weaker and the electrons are easily removed
what does atomic emission spectroscopy show evidence of
electrons are present within an atom in quantum shells
in what shell are electron energies lowest
the first shell
what occurs when additional energy is provided to electrons
they are temporarily excited into a higher state, they then return to their more stable, lower energy state. this causes discrete energies to be emitted
