High ionisation energy???

Hey guys god I'm so confused!!!!how do you get high ionisation energy and what are the reasons???

A high ionisation energy means a lot of energy is required to lose the electron.

3 things affect the ionisation energy:

1: Nuclear charge (the number of protons in the nucleus). The greater the number of protons in the nucleus, the stronger the attraction for the electrons.

2: Distance from the nucleus, an electron close to the nucleus (1S, 2S, 2P) is held more tightly than one further away (3S, 3P, 3D) therefore the closer the electron is to the nucleus the more energy it will require to remove it.

3: Shielding, the outer electrons will be shielded by the inner shells of electrons, so will have less attraction to the nucleus and be more easily lost (having a lower activation energy).

Hope that helps

Hey guys god I'm so confused!!!!how do you get high ionisation energy and what are the reasons???

Just to rephrase the great answer someone already gave, for something to have a high ionisation energy it would have to have a strong nuclear charge, a small atomic radius and as few electron shells as possible. Having these allows the nuclear charge of the nucleus to be felt more strongly by the electrons so they are more attracted to the nucleus and will thus require more energy to ionise and overcome this attraction.