Question

37 Which general trends in first ionization energy and electronegativity values are demonstrated by Group 15 elements as they are considered in order from top to bottom?(1) The first ionization energy decreases and the electronegativity decreases.
(2) The first ionization energy increases and the electronegativity increases.
(3) The first ionization energy decreases and the electronegativity increases.
(4) The first ionization energy increases and the electronegativity decreases.

Answer 1

The correct statement regarding the first ionization energy and electronegativity values in group 15 is as follows:

$\boxed{\left( 1 \right){\text{ The first ionization energy decreases and the electronegativity decreases}}}$

Further Explanation:

The amount of energy needed for the removal of the most loosely bound electron from a neutral isolated gaseous atom is termed as ionization energy, represented by IE. It depends on the ease of electron removal from the neutral atoms. If the electrons are removed easily, ionization energy will be less and vice-versa.

Ionization energy is called the first ionization energy when the first electron is removed from the atom. It is shown by $\left( {{\text{I}}{{\text{E}}_{\text{1}}}} \right)$. Similarly, if the second electron is removed, ionization energy becomes the second ionization energy $\left( {{\text{I}}{{\text{E}}_{\text{2}}}} \right)$.

The tendency of any element for electron attraction towards itself in a chemical bond is known as electronegativity. More the attracting tendency of the atom for electron, higher will be its electronegativity and vice-versa.

Atomic number and number of shells increase while going down group 15. Due to this, atomic size increases in the group from top to bottom. This increase in size results in weaker attractions between the outermost electrons and the atomic nucleus. So electrons are removed easily and therefore the first ionization energy decreases down this group.

Since atomic size increases from top to bottom of group 15, the attraction between the atomic nucleus and the electrons decreases. Therefore electronegativity also decreases down this group.

Therefore both the first ionization energy and electronegativity decrease down group 15.

Learn more:

1. Rank the elements according to first ionization energy: brainly.com/question/1550767
2. Arrange the following elements from greatest to least tendency to accept an electron: brainly.com/question/2107660

Answer details:

Grade: Senior School

Chapter: Periodic classification of elements

Subject: Chemistry

Keywords: ionization energy, first ionization energy, electronegativity, attraction, group 15, decrease.

Answer 2

Correct answer: The first ionization energy decreases and the electronegativity decreases.

Reason:
As we move from top to bottom in a periodic table, atomic radius increases. Also, effective nuclear charge decreases. Due to this, energy required to remove the electron form valance shell decreases. Hence, ionization energy decreases from top to bottom.

In addition to this, metallic character increases from top to bottom. Metals have low  electronegativity as compared to non-metals. Hence, electronegativilty value decreases from top to bottom.