Saved Bookmarks
| 1. |
What is ionization energy how it is differ in periods and groups? |
| Answer» Ionization energy is\xa0the minimum amount of energy required to remove an electron (to infinity) from the atom or molecule in the gaseous stateIonization energy is the quantity of energy that an isolated, gaseous atom in the ground electronic state must absorb to discharge an electron, resulting in a cation.H(g)→H+(g)+e−This energy is usually expressed in kJ/mol, or the amount of energy it takes for all the atoms in a mole to lose one electron each.These are the factors that affect ionization energy:\tAtomic radius\tNuclear charge\tOrbital penetration\tElectron pairing within a sub-shell\tShielding or screening effect of the inner orbitalsAtomic radius: When an atomic radius decreases, ionization energy increases.Across a period, atomic radius decreases. Down a group, atomic radius increases. Therefore, across a period ionization energy increases down a group it decreases.Nuclear charge: If a nucleus has a positive charge, there is a stronger attraction for the electrons. This results in a high amount of ionization energy. Across a period, attraction of electrons from the nucleus increases, while down a group it decreases. Therefore, across a period ionization energy increases down a group it decreases.Orbital penetration: Since the s orbitals penetrate towards the nucleus more closely than the p orbitals, it\'s easier to remove electrons from p orbitals than from s orbitals. Therefore, across a period ionization energy increases down a group it decreases.Electron pairing within a sub-shell: Since repulsion between electrons in the same orbital is higher than repulsion between electrons in different orbitals, within a sub-shell, paired electrons are easier to remove than unpaired ones. Across a period ionization energy increases, down a group it decreases.Shielding or screening effect of the inner orbitals: Electrons in the outermost orbitals feel lesser attraction from the nucleus than expected, due to presence of electrons in inner orbitals. Therefore, across a period ionization energy increases, down a group it decreases.Overall: across a period ionization energy increases and down a group ionization energy decreases.\xa0 | |