Because in Boron there is a complete 2s orbital and the increased shielding of the 2s orbital reduces the ionisation energy compared to that seen in Beryllium.
Barium has more energy levels. So it has lesser ionization energy.
Ionization energy generally increases across a period as a result of a higher nuclear charge, however there are some exceptions such as Boron which has a lower ionization energy than Beryllium (because it is in a P orbital), and Oxygen which has a lower ionization energy than nitrogen (Because ionization decreases the electron electron repulsion in its orbitals).
The symbol of beyllium is two letters. Be
The symbol of beyllium is two letters. Be
Generally, any element with a lower atomic number.
The rise in ionisation energy is not regular. To explain this we must remember that the second shell of electrons is actually subdivided into 2s and 2p. The most easily removed electron in Boron is that in the 2p orbital, higher in energy than the 2s electrons in Beryllium. It therefore needs less energy for total removal than does the 2s electron of Boron. This outweighs the effect of the increased nuclear charge of Boron, which tends to make its outer electron harder to remove.
Barium has more energy levels. So it has lesser ionization energy.
There are 12 such elements and they are hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon, sodium and magnesium.
The atomic no of Boron is 5 , so two electrons in ist shell the last three electrons are divided in two sub energy levels two in lower level 's' and one in higher level 'p'
Ionization energy generally increases across a period as a result of a higher nuclear charge, however there are some exceptions such as Boron which has a lower ionization energy than Beryllium (because it is in a P orbital), and Oxygen which has a lower ionization energy than nitrogen (Because ionization decreases the electron electron repulsion in its orbitals).
Ba, because it is lower on the periodic table
The maximum capacity of electron accommodation in aluminium is 18 electrons( M shell) on contraty it has only 3 valence electrons whereas boron has maximum capacity of 8 electrons(L shell) and it has 3 valence electrons so electron population of Aluminium is less than that of boron.
The symbol of beyllium is two letters. Be
The symbol of beyllium is two letters. Be
Because fluorine's size is lower than that of iodine, it has a greater ionization energy than iodine. Fluorine, on the other hand, appears to have a smaller shielding effect. As a result, fluorine's nucleus attracts more valence electrons than iodine's.
Generally, any element with a lower atomic number.
Generally, any element with a lower atomic number.