What is the unit of ionization energy?
The first ionization energy of element A is defined as the energy required by an atom to form A + ions. The unit of ionization energy is given as KJ mol -1.
What happens to the atomic number as you move down a group?
While moving down in a group, the atomic number increases and the number of shells also increases. Outermost electrons are far away from the nucleus and thus can be removed easily. The second factor that decreases the ionization energy is the shielding effect due to an increasing number of shells as we move down a group.
Why do electrons move closer to the nucleus?
The valence electrons get closer to the nucleus of an atom as we move from left to right due to increased nuclear charge. The force of attraction between the nucleus and the electrons increases and hence more energy is required to remove an electron from the valence shell. ...
What happens when an electron is removed from an atom?
Whenever an electron is removed from an atom, a specific amount of energy is required to remove it, hence the ionization enthalpies of chemical elements are always positive. The second most outer electron will be more attracted by the nucleus than the first outer electron.
What is the force of attraction between electrons and the nucleus?
The force of attraction between electrons and the nucleus. The force of repulsion between electrons. The effective nuclear charge felt by the outermost electrons will be less than the actual nuclear charge. This is because the inner electrons will shield the outermost electrons by hindering the path of nuclear charge.
Which electrons are shielded in Na?
For example, In Na, the 3s 1 electrons will be shielded by its core electrons (1s 2, 2s 2 and 2p 6 ). Generally, the shielding effect is more prominent when the inner orbitals are completely filled.
