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Ionic or Covalent Worksheet with Answers (Grade 11 Chemistry)

Q: Is this ionic or covalent worksheet free?

Yes. The worksheet and its answer key are free to download and print as a PDF, with no account needed.

Q: How do you tell if a bond is ionic or covalent?

Subtract the smaller electronegativity from the larger. A difference of 0–0.4 is nonpolar covalent, 0.5–1.7 is polar covalent and 1.8 or more is ionic.

Q: Is HF ionic or covalent?

Covalent. Its electronegativity difference is 1.9, but hydrogen and fluorine are both non-metals that share electrons, so H–F is a very polar covalent bond.

Q: Why do different textbooks use different cut-offs?

Bond character is a continuum, not three separate boxes. Most Grade 11 texts use about 1.7 for ionic; some use 1.8 or 2.0. Use the scale your course uses.

Q: What grade is this ionic or covalent worksheet for?

It is written for Grade 11 chemistry (Ontario SCH3U) and works for any introductory high school chemistry course.

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📄 Ionic or Covalent Worksheet with Answers (Grade 11 Chemistry)

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Practise classifying chemical bonds with this free Grade 11 chemistry worksheet.

This free ionic or covalent worksheet teaches Grade 11 students to decide how atoms bond using one reliable tool: the electronegativity difference (ΔEN).

Students calculate ΔEN for ten bonds, rank bonds by polarity, label partial charges, compare the properties of ionic and covalent compounds, and use lab evidence to identify unknown substances. A complete answer key is included.

Grade 11 · SCH3U
32 marks
30–40 minutes
Answer key included

What's in This Ionic or Covalent Worksheet

The sheet starts with calculation, then moves to properties and real lab evidence, so students see why bond type matters.

Part	Skill practised	Marks
A	Calculate ΔEN and classify 10 bonds	10
B	Rank bonds from least to most polar	2
C	Label partial charges (δ+ and δ−)	4
D	Compare ionic and covalent compounds	6
E	Classify compounds as ionic or covalent	6
F	Lab detective: identify bond type from evidence	2
G	Challenge: the HF puzzle and ionic character	2

It matches the Ontario SCH3U expectations for chemical bonding in the Matter, Chemical Trends and Chemical Bonding unit.

How to Tell if a Bond Is Ionic or Covalent

Every question on this ionic or covalent worksheet uses the same two-step method, and the PDF prints the reference on page 1.

Find ΔEN. Subtract the smaller electronegativity from the larger. For H–Cl: 3.0 − 2.1 = 0.9.
Read the scale. 0.9 falls between 0.5 and 1.7, so H–Cl is polar covalent, and chlorine carries the partial negative charge.

0–0.4
nonpolar covalent

0.5–1.7
polar covalent

1.8 and up
ionic

These are the Pauling values used on the worksheet. Metals are shaded purple and non-metals teal:

H2.1
Li1.0	Be1.5	B2.0	C2.5	N3.0	O3.5	F4.0
Na0.9	Mg1.2	Al1.5	Si1.8	P2.1	S2.5	Cl3.0
K0.8	Ca1.0					Br2.8
						I2.5

The cut-offs are guidelines on a continuum, not sharp walls, which is why Part G asks about HF. Electronegativity follows the patterns from our periodic trends worksheet, so that sheet makes a good warm-up. For the full table of values, see the electronegativity article on Wikipedia or Ptable.

Ionic or Covalent Practice Questions

These are the same questions as in the ionic or covalent worksheet PDF. Use the values above, then open the answer boxes to check.

Part A – Calculate ΔEN and Classify Each Bond

#	Bond	ΔEN	Bond type
1.	Na–Cl
2.	H–Cl
3.	C–H
4.	O–H
5.	K–F
6.	C–O
7.	Cl–Cl
8.	Mg–O
9.	N–H
10.	S–H

Part B – Rank by Bond Polarity

Least → most polar: C–H, O–H, N–H
Least → most polar: C–F, C–Cl, C–O

Part C – Partial Charges

Label which atom is δ− and which is δ+.

H–Cl
O–H
C–F
N–H

Part D – Compare Ionic and Covalent Compounds

#	Property	Ionic compounds	Covalent compounds
17.	How the bond forms
18.	Elements usually involved
19.	State at room temperature
20.	Melting point
21.	Conducts electricity when molten or dissolved
22.	Example

Part E – Ionic or Covalent Compound?

Hint: metal + non-metal is usually ionic; two non-metals are covalent.

NaCl
CO₂
MgO
H₂O
CaF₂
NH₃

Part F – Lab Detective

A white solid melts at 801 °C, dissolves in water, and the solution conducts electricity. Ionic or covalent?
A clear liquid boils at 80 °C and does not conduct electricity. Ionic or covalent?

Part G – Challenge

The H–F bond has ΔEN = 1.9, above the 1.7 cut-off, yet HF is a covalent molecule. Explain.
Which has more ionic character, LiF or NaCl? Show your ΔEN values.

Ionic or Covalent Worksheet Answer Key

Open each part to check your work. The printable answer key is on pages 3–4 of the PDF.

Part A answers (Q1–10)

#	Bond	ΔEN	Bond type
1.	Na–Cl	2.1	Ionic
2.	H–Cl	0.9	Polar covalent
3.	C–H	0.4	Nonpolar covalent
4.	O–H	1.4	Polar covalent
5.	K–F	3.2	Ionic
6.	C–O	1.0	Polar covalent
7.	Cl–Cl	0.0	Nonpolar covalent
8.	Mg–O	2.3	Ionic
9.	N–H	0.9	Polar covalent
10.	S–H	0.4	Nonpolar covalent

Part B answers (Q11–12)

C–H (0.4) < N–H (0.9) < O–H (1.4)
C–Cl (0.5) < C–O (1.0) < C–F (1.5)

Part C answers (Q13–16)

Cl is δ−, H is δ+
O is δ−, H is δ+
F is δ−, C is δ+
N is δ−, H is δ+

Part D answers (Q17–22)

#	Property	Ionic compounds	Covalent compounds
17.	How the bond forms	Electrons transferred (ions form)	Electrons shared
18.	Elements usually involved	Metal + non-metal	Non-metal + non-metal
19.	State at room temperature	Crystalline solid	Gas, liquid or soft solid
20.	Melting point	High	Low
21.	Conducts electricity when molten or dissolved	Yes	No (usually)
22.	Example	NaCl, MgO	H₂O, CO₂

Part E answers (Q23–28)

NaCl: Ionic
CO₂: Covalent
MgO: Ionic
H₂O: Covalent
CaF₂: Ionic
NH₃: Covalent

Part F answers (Q29–30)

Ionic: high melting point and conducts when dissolved.
Covalent: low boiling point and no free ions to carry charge.

Part G answers (Q31–32)

Both are non-metals and share electrons; the ΔEN cut-offs are guidelines on a continuum, so H–F is best described as a very polar covalent bond.
LiF: ΔEN = 4.0 − 1.0 = 3.0, greater than NaCl’s 3.0 − 0.9 = 2.1.

5 Common Ionic vs Covalent Mistakes

These errors come up every year, and the ionic or covalent worksheet is built to catch them.

Getting a negative ΔEN. Always subtract the smaller value from the larger. ΔEN is never negative.
Calling every polar bond ionic. O–H has ΔEN = 1.4. It is very polar, but the electrons are still shared.
Putting δ− on the wrong atom. The more electronegative atom pulls the electrons and carries δ−.
Assuming any hydrogen compound is ionic or any compound with a metal is covalent. Check whether you have a metal + non-metal or two non-metals.
Treating the cut-offs as exact. Bonds near 1.7 have mixed character. HF is the classic example.

How to Use This Ionic or Covalent Worksheet in Class

As a teacher, I use it in three ways depending on where students are in the bonding unit:

Lesson practice: Parts A–C right after introducing electronegativity, about 15 minutes.
Homework: Parts D–G, which link bond type to properties and lab evidence.
Lab tie-in: Use Part F before a conductivity or melting-point lab so students predict results first.

Then check understanding with our ionic vs covalent bonding quiz and the chemical bonding quiz, both auto-graded with 20 questions.

Frequently Asked Questions

Is this ionic or covalent worksheet free?