Question

Which statements are true about electronegativity? (a) Electronegativity increases from left to right in a period of the Periodic Table. (b) Electronegativity increases from top to bottom in a column of the Periodic Table. (c) Hydrogen, the element with the lowest atomic number, has the smallest electronegativity. (d) The higher the atomic number of an element, the greater its electronegativity.

Short answer

Answer: Electronegativity increases from left to right in a period of the Periodic Table.

Step-by-step solution

Define electronegativity

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The most common scale to measure electronegativity is the Pauling scale, which ranges from around 0.7 (francium) to 4.0 (fluorine).

Recall important properties of electronegativity

Some important properties of electronegativity are: 1. Electronegativity increases from left to right across a period of the periodic table. 2. Electronegativity decreases from top to bottom down a group (column) of the periodic table. 3. The noble gases have low electronegativities due to their stable electron configuration. 4. The most electronegative element is fluorine, while the least electronegative element is francium.

Analyze each statement

(a) Electronegativity increases from left to right in a period of the Periodic Table. This statement is consistent with property 1 mentioned in Step 2. Therefore, statement (a) is true. (b) Electronegativity increases from top to bottom in a column of the Periodic Table. This statement contradicts property 2 mentioned in Step 2. Electronegativity decreases from top to bottom down a group. Therefore, statement (b) is false. (c) Hydrogen, the element with the lowest atomic number, has the smallest electronegativity. Hydrogen is not the element with the smallest electronegativity, as stated in property 4 of Step 2. The element with the smallest electronegativity is francium. Therefore, statement (c) is false. (d) The higher the atomic number of an element, the greater its electronegativity. The trend of increasing electronegativity with increasing atomic number is not entirely accurate. Electronegativity increases across a period and decreases down a group as mentioned in properties 1 and 2 in Step 2. Therefore, statement (d) is false. So, the only true statement about electronegativity among the given options is statement (a).