Why does ionization energy tend to decreases from top to bottom within a group?

Answer 1

Atomic Radius increases down a group. Also, the electrons become farther away from the nucleus. The electron numbers increase and therefore they go into shells farther from the nucleus. This makes it easier to strip an electron from an atom.

Answer 2

Ionisation energy increases as you go down a group. The reactivity increases on descending the group from lithium to caesium. As you go down the group the period number is increasing so the number of electron shells is also increasing so the forces between the oppositely charged electrons and nucleus are lower. This makes it easier for the elements such as rubidium and caesium to react and gain electrons. All group one metals have one electron in their outer shell which makes it easy for them to react with other elements.

Answer 3

Ionization energy decreases top to bottom of a group (going down the column) due to the fact that as you move down the periodic table, not only does nuclear charge decrease but more importantly, the distance between the positively charged nucleus and the negatively charged electrons increases. Thus, the nucleus has a lesser hold and attraction to the electrons, allowing less energy to pull them away.

Answer 4

Ionization energy goes down as u go down a period bc there is more sheilding so the nuclear pull is less effective. Thus, it is easier, and takes less energy, to remove an electron and inonize

Answer 5

As you go down a group, a shell is added to the atom with every period. This makes the elements bigger and valence shell away from the nucleus. This reduces the force of attraction between nucleus and the valence electrons and thus, the ionization energy is reduced.

Answer 6

Ionisation energies always decrease down a group. That's because it depends upon 3 factors:

1)Distance between nucleus & the valence electron

2)The positive charge on the nucleus (number of protons)

3)The shielding effect of inner shell electrons

As we go down the group, the number of shells increase as does the distance between the valence electrons and the nucleus. Although the number of protons increases down the group, attraction between the nucleus and valence electrons decreases due to the shielding effect of more electrons in filled inner shells and also due to the increased distance between them.

Answer 7

The farther you move down a group, the farther the outermost electron is from the nucleus. The farther away an electron is from the nucleus, the weaker the attractive force holding them together is. The weaker the attractive force, the lower the energy it takes to separate them, and hence the lower the First Ionization Energy.

Why? Coulomb's law -- the force of attraction between two oppositely charged particles -- or the force of repulsion between two particles of the same charge -- is proportional to the charges on both particles, and is inversely propotional to the square of hte distance between them. Therefore, the farther away two oppositely charged objects are (for example, a positively charged nucleus and a negatively charged electron), the weaker the attraction between them is, and the lower the energy it takes to separate them.

Answer 8

Ionization energy is the energy to remove an electron from an atom. From top to bottom, the atom gets larger, so electrons are farther from the nucleus and have a smaller attraction force so it is easier, takes less energy, to remove an outer electron.

Answer 9

With the decrease in pull, less ionization energy is required thus the trend in ionization energy, decreases from top to bottom.