Question

The following graph shows the first ionization energy for elements through period 6. 2500 puntos Period 4 Periods Period Ionization energy (kJ/mole) Ionization energy (OV) Atomic Number There is a slight decrease in ionization energy as group 13 (B, Al, Ga, In, Tl) is reached. How would you explain this observation? (1 pt) In a varitational method calculation, what purpose does a variational parameter serve? (1 pt)

Answer 1

• This question is based upon periodicity of elements.
• Ionization energy is the type of energy which is required to remove an electron from the outermost shell of gaseous atom or an ion.
• The energy which is required to remove one mole of electron from one mole of isolated gaseous atoms or ions is known as the first or initial ionization energy of an atom or molecule. The first or initial ionization energy is represented by the symbol of  "E_i ".

The general trend of ionization energy is as follows:

• When we move from left to right across a period, the atomic radius of an atom or ion decreases due to this the electrons of atoms or ions starts become more attracted towards the nucleus and remove an electron from outermost shell become so difficult and therefore across a period the ionization energy increases.
• In a group, when we move from top to bottom down a periodic table group a valence shell is added and remove an electron is easier from outermost shell and therefore ionization energy decreases in moving down a group.

The general trend for first ionization energy is as follows:

• When we move from left to right within a period or upward in a group, the first ionization energy generally increases.

• The group 13 (XIII) elements consists of total six elements of the p block in the Periodic Table of elements which are as follows:
• Boron (B), Aluminium (Al), Gallium (Ga), Indium (In) and Thallium (Tl).
• The common property of the group 13 elements is that each elements has three electrons in their outer electronic configuration of their nuclear structure.
• The more electrons shielding the outer electron shell from the nucleus, the less energy is required to remove an electron from an atom. This is the reason and because of the shielding effect, the ionization energy decreases from top to bottom down the group. The atoms of the Groups 13 elements lose their one electron easily from outer shell in order to achieve the stable noble gas configuration. Therefore the ionization energy is lower.