Question

electronegativity worksheet
name
block

1. how are ionic bonds and covalent bonds different?
2. how does a polar covalent bond differ from a non - polar covalent bond?
3. how do electronegativity values help us determine the polarity of a bond?
4. fill in the values to complete the following table for predicting bond type based on differences in electronegativity.
5. does electronegativity increase or decrease when you go across a period on the periodic table? does it increase or decrease when you move down a group on the periodic table?
6. for each of the following sets of elements, identify the element expected to be most electronegative (circle) and which is expected to be least electronegative (cross out), based on their position in the periodic table.

a. k, sc, ca
b. br, f, at
c. c, o, n

Explanation:

• Question 1: Ionic bonds involve the transfer of electrons (usually between a metal and a non - metal), creating ions that are held together by electrostatic forces. Covalent bonds involve the sharing of electrons (usually between non - metals).
• Question 2: In a polar covalent bond, electrons are shared unequally due to a difference in electronegativity between the atoms. In a non - polar covalent bond, electrons are shared equally (electronegativity difference is very small or zero).
• Question 3: Calculate the electronegativity difference ($\Delta EN$) between the two atoms in the bond. If $\Delta EN = 0$ (or very close to 0, say $<0.3$), it's non - polar covalent. If $0.3\leq\Delta EN<1.8$, it's polar covalent. If $\Delta EN\geq1.8$, it's ionic.
• Question 4: The values for the table (from left to right) are based on the general rules of electronegativity difference for bond type: non - polar covalent ($0 - 0.3$), polar covalent ($0.3 - 1.8$), ionic ($\geq1.8$).
• Question 5: Across a period (left to right), electronegativity increases (more protons in the nucleus attract electrons more). Down a group (top to bottom), electronegativity decreases (electrons are in higher energy levels, farther from the nucleus).
• Question 6a: In the third period, $K$ (potassium) is the left - most among $K$, $Sc$ (scandium), and $Ca$ (calcium). Since electronegativity increases across a period, $K$ is the least electronegative.
• Question 6b: In the halogen group, $At$ (astatine) is the bottom - most among $Br$ (bromine), $F$ (fluorine), and $At$. Since electronegativity decreases down a group, $At$ is the least electronegative and $F$ is the most electronegative.
• Question 6c: In the second period, $C$ (carbon) is the left - most among $C$, $O$ (oxygen), and $N$ (nitrogen). Since electronegativity increases across a period, $C$ is the least electronegative.

Answer:

1. Ionic bonds: electron transfer (metal - non - metal, electrostatic). Covalent bonds: electron sharing (non - metal - non - metal).
2. Polar covalent: unequal electron sharing (electronegativity difference). Non - polar covalent: equal sharing ($\Delta EN\approx0$).
3. Calculate $\Delta EN$: $0 - 0.3$ (non - polar), $0.3 - 1.8$ (polar), $\geq1.8$ (ionic).
4. Values (left to right): $0.3$, $1.8$.
5. Across a period: increases. Down a group: decreases.

6.
a. Circle none (if only least is to cross - out: cross - out $K$).
b. Circle $F$, cross - out $At$.
c. Circle none (if only least is to cross - out: cross - out $C$).