Ionization energy -
"Is the amount of energy required to remove an electron from the outermost shell of gaseous atom"
" Is a measure of the capability of an element to enter into chemical reactions requiring ion formation or donation of electrons"
Unit - Measured in Joule / mole
Ionization energy depends upon the size of an an atom and nuclear charge.
If the higher ionization energy it means removal of an electron is difficult from that atom.
Ionization energy increases in period
as we move from left to right size of an atom increases because of more nuclear charge so removal of an electron become difficult from left to right as the result ionization energy increases from left to right
Ionization energy Decreases along the group
Because the size of an atom will increase from top to bottom along shell number - so there is distance between the outermost electron and nucleus the it easy to remove the electron
