Question

Fill in the blanks with appropriate option. The ability of an atom to attract shared electrons to itself is called (i). It is generally measured on the (ii) scale. An arbitrary value of (iii) is assigned to fluorine (have greatest ability to attract electrons). It generally (iv) across a period and (v) down a group. (i) (ii) (iii) (iv) (v) (a) polarity Pauling \(2.0\) decreases increases (b) electro- Pauling \(4.0\) increases decreases negativity (c) valency Mulliken \(1.0\) decreases increases (d) electron Mulliken \(2.0\) increases increases affinity \(\longrightarrow\)

Short answer

The correct option is (b) electronegativity, Pauling, 4.0, increases, decreases.

Step-by-step solution

Identifying the Concept of Electron Attraction

The ability of an atom to attract shared electrons is referred to as 'electronegativity'. Therefore, option (i) should be a term that denotes this specific ability.

Recognizing the Scale for Electronegativity

Electronegativity is measured on a particular scale devised by Linus Pauling. The correct scale for option (ii) is named after this chemist.

Assigning the Arbitrary Value to Fluorine

On the Pauling scale of electronegativity, fluorine is assigned the highest value since it has the greatest ability to attract electrons. The correct arbitrary value for option (iii) should reflect this fact.

Trend Across a Period

In the periodic table, electronegativity increases as one moves from left to right across a period. Therefore, the correct term for option (iv) should indicate this increasing trend.

Trend Down a Group

Moving down a group in the periodic table, the electronegativity of atoms generally decreases because the added electron shells reduce the attraction between nucleus and valence electrons. The correct term for option (v) should reflect this decreasing trend.

Matching the Correct Option

Considering the information from the previous steps, look for the option that correctly fills in all the blanks: electronegativity, Pauling scale, arbitrary value for fluorine, trend across a period, and trend down a group.

Key concepts

Pauling Scale

Understanding the Pauling scale is essential for students delving into the world of chemistry, particularly when it comes to discussing the property of electronegativity. Developed by the Nobel laureate Linus Pauling, this scale quantifies the ability of an atom within a molecule to attract shared electrons, a characteristic that is central to the formation of chemical bonds.

The Pauling scale operates with dimensionless numbers, making it a relative scale where different elements are compared to each other. The higher the value, the greater an atom's power to attract electrons. The standard was set by assigning an arbitrary value to the most electronegative element, fluorine. This element serves as a reference point against which all other elements' electronegativity values are gauged.

For students, it's critical to realize that there is no actual unit for these values, since they are based on observations of bond energies in compounds, not direct measurements. This concept often proves challenging, so emphasizing its comparative nature helps in grasping why certain elements behave differently in chemical reactions due to their varying electronegativities.

Periodic Trends

Periodic trends refer to patterns in the properties of elements that are apparent as one moves across the Periodic Table of the Elements. These trends are crucial for predicting the chemical behavior of an element, and electronegativity is one such property that showcases a predictable trend.

Electronegativity Across a Period

From left to right across a period, atoms generally become more electronegative. This is due to the increasing positive charge of the nuclei, which draws the bonding electrons more strongly. As electrons are added to the same energy level and the nucleus gains protons, the attraction for electron pairs increases, hence the rise in electronegativity.

Electronegativity Down a Group

Conversely, going down a group, electronegativity decreases. This trend results from the larger atomic radii and the greater number of electron shells in atoms, which distance the valence electrons from the nucleus, weakening the pull on shared electrons.

Recognizing these trends is not just about memorizing changes in electronegativity; it's about understanding the underlying reasons why these changes occur. This deeper comprehension aids students in predicting how atoms will interact in chemical compounds and can vastly improve their ability to handle complex concepts in chemistry.

Fluorine Electronegativity Value

Fluorine takes a special place in the discussion of electronegativity, as it is the most electronegative element with an assigned value of 4.0 on the Pauling scale. This high value means that fluorine has an unrivaled tendency to attract electrons towards itself when forming chemical bonds.

In the context of the original exercise, this is the key piece of information necessary to complete the answer correctly. The value not only serves as an important reference point but also anchors the electronegativity scale, enabling comparisons among elements. For many students, understanding the exceptional nature of fluorine's electronegativity can be the first step towards appreciating the intricate patterns of chemical behavior demonstrated across the periodic table.

It is crucial for educators to emphasize the significance of this value, illustrating how it impacts the formation of fluorine-containing compounds, such as in its high reactivity and the strong bonds it forms. This particular discussion can help students to better visualize and predict the potential outcomes of reactions involving this highly electronegative element.