1.6- ELECTRON ARRANGEMENT AND IONISATIONE ENERGY Flashcards
What provides evidence for electron energy sub-levels?
patters in first ionisation energy
What is the definition of ionisation energy?
energy required to remove a mole of electrons from a mole of atoms in the gaseous state
What is ionisation energy measured in?
kJmol^-1
What is the abbreviation for ionisation energy?
IE
What is successive ionisation energy?
first ionisation energy needs least amount of energy
second needs more
third needs even more
Change of ionisation energy along a period and why?
generally increase because nuclear charge is increasing which makes it more difficult to remove an electron
Why does the ionisation energy decrease going from magnesium to aluminium
despite the nuclear charge increase, the outer electron in aluminium is in the 3p orbital which is of slightly higher energy than the 3s orbital
Why is there a slight drop in ionisation energy between phosphorus and sulfur?
in phosphorus, each of the three 3p orbitals contains just one electron
in sulfur, one of the 3p orbitals must contain 2 electrons. Repulsion between these paired electrons makes it easier to remove one of them, despite increase in nuclear charge
What is the cases that go against the expected trend evidence for?
confirms existence of s- and p- orbitals predicted by quantum theory and Schrödinger equation
What is the general pattern in first ionisation energy for Group 2 and why?
general decrease and same pattern seen in other groups
because outer electron is in a main level that gets further from the nucleus in each case
What happens to nuclear charge going down a group?
nuclear charge increases
Why does nuclear charge increase going down a group?
effect of inner electrons shielding nuclear charge
