SME
Grade 10 Science · Problem type
Electronegativity
Use this to see which atom in a bond pulls the shared electrons harder.
Diagram
Electronegativity of Fluorine: 3.98.
Nitrogen: 3.04, so F has the higher value.
Electronegativity increases across a period and decreases down a group; the stronger the shade, the larger the value.
Dashed cells have no value: helium, neon and argon form no compounds.
Difference (first − second): 0.94
This is an example. Type your own values to start a new problem.
Δx
=
x₁
−
x₂
Z₁
Atomic number of the first element
example
Z₂
Atomic number of the second element
example
Formulas
x₁
=
electronegativity
of
element
Z₁
3.98 = electronegativity of element 9
x₂
=
electronegativity
of
element
Z₂
3.04 = electronegativity of element 7
Δx
=
x₁
−
x₂
0.94 = 3.98 − 3.04
Assumptions
•
Electronegativity is on the Pauling scale, with no unit; fluorine is highest, 3.98.
•
It rises across a period and falls down a group.
•
The noble gases helium, neon and argon have no value.
Step-by-step
WE KNOW
Z₁ = 9, Z₂ = 7
FIND
electronegativity of the first element (x₁), electronegativity of the second element (x₂), difference (first − second) (Δx)
Step 1 · Find electronegativity of the first element (x₁)
Use x₁ = electronegativity of element Z₁
Read the element’s electronegativity from the table.
x₁
=
electronegativity
of
element
9
Z = 9 (fluorine): period 2, group 17
x₁
=
3.98
Step 2 · Find electronegativity of the second element (x₂)
Use x₂ = electronegativity of element Z₂
Read the element’s electronegativity from the table.
x₂
=
electronegativity
of
element
7
Z = 7 (nitrogen): period 2, group 15
x₂
=
3.04
Step 3 · Find difference (first − second): Δx
Use Δx = x₁ − x₂
Subtract to see which is larger, and by how much.
Δx = 3.98 − 3.04
Same period: Z = 9 is farther right, so the electronegativity of Z = 9 is the larger
Δx = 0.94
Check
Put the numbers back in. Both sides should match.
3.98 = electronegativity of element 9 ✓
3.04 = electronegativity of element 7 ✓
0.94 = 3.98 − 3.04 ✓
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.