Question

what's the meaning of ionization energy?! { class 10 reference}

Answer 1

Ionization energy is the energy required to remove an electron from a gaseous atom or ion. The first or initial ionization energy or Ei of an atom or molecule is the energy required to remove one mole of electrons from one mole of isolated gaseous atoms or ions.

Answer 2

hala mate,

Ionization basically means to create ions from an atom. An atom consists of proton, Neutron (in nucleus of an atom) and electrons (revolving around). When all this this atomic particle being combined in a single atom they do not have their own charge. Now ion is an independent particle which contains its own charge. The ionization energy is the energy which removes an electron from the atom and creates independent ions(electron as negatively charged particles and proton and positively charged particles).The process to create ions is called Ionization. As we apply appropriate energy to an atom it removes electron from the outer orbit and the removed electron now behaves as an ion. As the atomic number (No. of proton in a  nucleus of an atom) increases the amount energy to remove an electron from a orbit increases (due to more electromagnetic force between proton and electron).

hope it helps!!!