Ionisation energy

*using the as level syllabus*

Define and use the term first ionisation energy

Ionisation energy is the amount of energy required to remove an electron from an atom or ion in its gaseous state. It is a key factor in determining an element's reactivity and chemical properties.

Examples of equations that represent first, second and subsequent ionisation energies

include: 1st: Na(g) → Na+(g) + e−; 2nd: Na+(g) → Na2+(g) + e−; 3rd: Na2+(g) → Na3+(g) + e−.

What are the trends in ionisation energy across a period and down a group on the periodic table?

Ionisation energy increases across a period due to increasing nuclear charge and decreases down a group due to increased distance from the nucleus and electron shielding.

what is the causes of ionisation energies

The causes of ionisation energies include factors such as nuclear charge, electron shielding, and the distance of the outermost electrons from the nucleus, which influence the energy required to remove an electron from an atom.

What are the factors that influence ionisation energies?

The factors that influence ionisation energies include nuclear charge, atomic/ ionic radius ,electron shielding, and the distance of the outermost electrons from the nucleus, as well as spin-pair repulsion, which affect the energy needed to remove an electron.

How to deduce electronic configurations of elements using successive ionisation energy?

The electronic configurations of elements can be illustrated by their successive ionisation energies, which show the energy required to remove each subsequent electron, reflecting changes in nuclear charge and electron shielding as electrons are removed.

How to deduce the position of an element in the periodic table using successive ionisation energy

Successive ionisation energies can be used to deduce an element's position in the periodic table by analyzing the patterns in the energies required to remove electrons, indicating the number of valence electrons and the element's group.

What type of reaction is associated with ionisation energies

Ionisation energies are associated with endothermic reactions, where energy is absorbed to remove electrons from an atom or ion.