Electronic Structure Flashcards
What is ionisation energy
The energy needed to remove one mole of electrons from one mole of gaseous atoms of an element to form 1+ ions
Why are ionisations always endothermic
As energy is taken in by the reaction so positive energy change
How can ionisation energy be determined by using a spectroscope
Heating the atoms gives them energy which causes some of the electrons to jump to higher energy levels(excitation), each line in spectrum arises from energy given out as electrons drop back from higher energy level to a lower level
What are atomic energy levels and how does this relate to quantum theory
The energies of electrons in atoms, according to quantum theory each electron in an atom has a definitive energy, when lose or gain energy levels electrons jump from one energy level to another
Equation for first ionisation of sodium
Na(g)—>Na+(g) + e-
Why do successive ionisation elements for an element get bigger
Having removed one electron it is more difficult to remove a second electron from the positive ion formed
Why is outer electron removed first
As it is shielded from full attraction of the positive nucleus by inner electrons, also furthest from nucleus so electrostatic attraction decreases and has higher quantum energy so requires less energy to remove
When are electrons in the same orbital stable and why
Only stable when they spin in opposite directions so their magnetic attraction resulting from their opposite spins can counteract electrical repulsion from their negative charges
Why is log ionisation used
Makes it possible to fit all values on the vertical axis while still showing where there are big jumps in values
How to tell which group an element is in by its successive ionisation energies
When the first big jump in ionisation energies occurs can predict which group, as tells how many electrons on outer shell. Ionisation energy jumps by more than 3.5 times
