When we move from the bottom to the top of the periodic table:

Electronegativity increases and ionisation energy decreases

Both electronegativity and ionisation energy decreases

Both electronegativity and ionisation energy increases

They remain the same

When we move from the bottom to the top of the periodic table:

Both electronegativity and ionisation energy increases.

Explanation:

The ionization energy I is the energy needed to start an electron to a gaseous atom, isolated and in a fundamental state. The electrons are attracted to the nucleus, so it is necessary to provide energy to start them. You should keep in mind that the electrons of the last layer are always lost, because they are the weakest attracted to the nucleus.

In a group, the ionization energy increases upwards because when passing from one element to the bottom, it contains one more layer of electrons. Therefore, the valence layer electrons, being further away from the nucleus, will be less attracted to it and it will cost less energy to pluck them.

On the other hand, electonegativity is defined as the ability of an element to attract electrons that link it to another element.

When descending within the same group, the atomic radius increases and the ionization energy decreases, indicating that the electrons are less attracted to the nucleus and therefore the electronegativity decreases from top to bottom.