Loading

Why is the first ionisation energy of Sodium greater than the first ionisation energy of Caesium?

Sodium, element number 11, is positioned higher than Caesium, element 55, in the group 1 elements. The nuclear charge of increases down a group, due to a greater number of protons in the nucleus, as well as an increase in shielding, from greater number of electrons occupying the innermost energy levels. There will be therefore a weaker electrostatic interaction between valence shell electrons and the nucleus in Caesium than in Sodium. Leading to less energy required to remove one valence shell electron from Caesium than from Sodium.

A pair of laptops with a tutor displayed on one and a student on the other. The student is raising his hand to answer the teacher's question.
Need help with Chemistry?

Have a Free Video Meeting with one of our friendly tutors.

A pair of laptops with a tutor displayed on one and a student on the other. The student is raising his hand to answer the teacher's question.
Need help with Chemistry?

Have a Free Video Meeting with one of our friendly tutors.

A pair of laptops with a tutor displayed on one and a student on the other. The student is raising his hand to answer the teacher's question.
Need help with Chemistry?

Have a Free Video Meeting with one of our friendly tutors.