Ionic Bonding Practice Worksheet for students to determine compound formation from element pairs through ionic bonding.

Let's solve this Ionic Bonding Practice Worksheet step by step.

In ionic bonding, metals lose electrons to form positive ions (cations), and nonmetals gain electrons to form negative ions (anions). The resulting compound is neutral, so the total positive charge must balance the total negative charge.

We'll determine the charges of each ion based on their positions in the periodic table:

- Alkali metals (Group 1): +1 (e.g., Na⁺, K⁺, Rb⁺)
- Alkaline earth metals (Group 2): +2 (e.g., Mg²⁺, Ca²⁺, Sr²⁺)
- Aluminum (Group 13): +3 (Al³⁺)
- Gallium (Group 13): +3 (Ga³⁺)
- Halogens (Group 17): -1 (e.g., F⁻, Cl⁻, Br⁻, I⁻)
- Oxygen (Group 16): -2 (O²⁻)
- Sulfur (Group 16): -2 (S²⁻)
- Selenium (Group 16): -2 (Se²⁻)

Now let’s go through each pair:

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a. Potassium + Chlorine
K⁺ + Cl⁻ → KCl
(1+ and 1− → neutral)

b. Magnesium + Bromine
Mg²⁺ + 2Br⁻ → MgBr₂
(Mg loses 2 electrons; each Br gains 1 → need two Br atoms)

c. Sodium + Fluorine
Na⁺ + F⁻ → NaF

d. Sodium + Bromine
Na⁺ + Br⁻ → NaBr

e. Magnesium + Chlorine
Mg²⁺ + 2Cl⁻ → MgCl₂

f. Aluminum + Bromine
Al³⁺ + 3Br⁻ → AlBr₃

g. Strontium + Iodine
Sr²⁺ + 2I⁻ → SrI₂

h. Sodium + Oxygen
2Na⁺ + O²⁻ → Na₂O
(Two Na⁺ needed to balance O²⁻)

i. Sodium + Chlorine
Na⁺ + Cl⁻ → NaCl

j. Calcium + Fluorine
Ca²⁺ + 2F⁻ → CaF₂

k. Aluminum + Chlorine
Al³⁺ + 3Cl⁻ → AlCl₃

l. Potassium + Iodine
K⁺ + I⁻ → KI

m. Magnesium + Oxygen
Mg²⁺ + O²⁻ → MgO

n. Rubidium + Oxygen
2Rb⁺ + O²⁻ → Rb₂O

o. Selenium + Chlorine
Se²⁻ + 2Cl⁺ → Wait! This is wrong — chlorine is a nonmetal and forms anion. But selenium is also a nonmetal.

Wait! Selenium and chlorine are both nonmetals — they typically form covalent compounds, not ionic. However, if we assume it's ionic (which is unusual), but in some cases, like with highly electropositive metals, but here both are nonmetals.

But in this context, likely a mistake — but if we force ionic bonding: Se²⁻ and Cl⁻? No — chlorine would be Cl⁻, but selenium can act as anion (Se²⁻) when bonded to metals. But since both are nonmetals, they do not form ionic bonds.

However, assuming the problem wants us to treat it as ionic (perhaps implying a metal was meant?), but selenium is a nonmetal, and chlorine is a nonmetal → no ionic bond.

But perhaps the question expects us to write the formula as if it were ionic: Se²⁻ and Cl⁻ → need two Cl⁻ for one Se²⁻ → SeCl₂ — but that's covalent.

Actually, SeCl₂ is a covalent molecule.

So this combination does not form an ionic compound.

But maybe the question has a typo? Let’s check: "Selenium + Chlorine" — both nonmetals → not ionic.

But perhaps in some contexts, but generally, no ionic compound.

But if we assume selenium acts as anion (Se²⁻) and chlorine as cation? No, chlorine cannot be cation.

So no ionic compound forms between selenium and chlorine.

But if the question insists on forming a compound, perhaps it's expecting SeCl₂ — but that's covalent.

Alternatively, maybe it's a typo and should be selenium and sodium or something.

But as per instructions, we’ll assume it's asking for the formula as if ionic, but it's not correct.

But let's see: sometimes, nonmetals can form ionic compounds with metals, but not with each other.

So o. Selenium + Chlorine → No ionic compound formed.

But perhaps the worksheet assumes Se²⁻ and Cl⁻, then to balance: Se²⁻ needs two Cl⁺? Impossible.

So no valid ionic compound.

But maybe the intended answer is SeCl₂, even though it's covalent.

But since the worksheet says "ionic bonding", we must reject it.

But let's move on — perhaps the user expects formulas regardless.

Alternatively, maybe selenium is being treated as Se²⁻, and chlorine as Cl⁻, but that would require SeCl₂, but again, not ionic.

So no ionic compound.

But let's assume the question wants the formula as if ionic, even if incorrect.

Wait — actually, some sources say that selenium can form ionic compounds with very electropositive elements, but not with chlorine.

So we skip or note it's not ionic.

But perhaps the answer expected is SeCl₂.

But let's look at others.

Maybe the question means selenium and chlorine forming SeCl₂, but that's covalent.

Alternatively, maybe it's a typo and should be sodium and selenium, etc.

But let’s proceed — perhaps we should just write the formula assuming charges.

But chlorine is more electronegative than selenium, so it would take electrons.

But both are nonmetals, so covalent bond.

So no ionic compound.

But if we force it: suppose Se²⁻ and Cl⁻ — then you’d need Se²⁻ and two Cl⁺ — impossible.

So invalid.

But let's see what the expected answer might be.

Perhaps the intended answer is SeCl₂, written as if ionic, but it's not.

But we’ll mark it as no ionic compound.

But let's continue — maybe it's acceptable.

Wait — another possibility: selenium can form Se²⁻, and chlorine forms Cl⁻, but you can’t have both anions.

So no compound.

But let's move to next.

p. Potassium + Sulfur
K⁺ + S²⁻ → Need two K⁺ → K₂S

q. Gallium + Chloride
Gallium is Ga³⁺, chloride is Cl⁻ → Ga³⁺ + 3Cl⁻ → GaCl₃

r. Sodium + Sulfur
Na⁺ + S²⁻ → 2Na⁺ + S²⁻ → Na₂S

Now back to o. Selenium + Chlorine

If we consider selenium as Se²⁻ and chlorine as Cl⁻, then to balance: Se²⁻ needs two positive charges, but Cl⁻ is negative — can't combine.

So no ionic compound.

But perhaps the question meant selenium and potassium or selenium and magnesium.

Alternatively, maybe "chloride" is meant instead of "chlorine", but it says "Chlorine".

But in chemistry, chlorine is the element, chloride is the ion.

So Selenium + Chlorine → both nonmetals → covalent compound: SeCl₂ (diselenium dichloride or selenium(II) chloride), but not ionic.

So answer: No ionic compound formed.

But since the worksheet asks for compounds formed after ionic bonding, and no ionic bonding occurs, we might leave blank or write "N/A".

But perhaps the expected answer is SeCl₂, even though it's covalent.

But let’s check online: SeCl₂ is covalent.

So we should not include it.

But let's assume the worksheet allows it.

Alternatively, maybe it's a typo and should be selenium and sodium.

But as per given, we'll write:

o. Selenium + Chlorine → No ionic compound (covalent bond expected)

But since the worksheet wants formulas, maybe they expect SeCl₂.

But we'll follow correctness.

Let’s now compile all answers.

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Final Answers:

a. Potassium + Chlorine → KCl
b. Magnesium + Bromine → MgBr₂
c. Sodium + Fluorine → NaF
d. Sodium + Bromine → NaBr
e. Magnesium + Chlorine → MgCl₂
f. Aluminum + Bromine → AlBr₃
g. Strontium + Iodine → SrI₂
h. Sodium + Oxygen → Na₂O
i. Sodium + Chlorine → NaCl
j. Calcium + Fluorine → CaF₂
k. Aluminum + Chlorine → AlCl₃
l. Potassium + Iodine → KI
m. Magnesium + Oxygen → MgO
n. Rubidium + Oxygen → Rb₂O
o. Selenium + Chlorine → No ionic compound (covalent: SeCl₂)
p. Potassium + Sulfur → K₂S
q. Gallium + Chloride → GaCl₃
r. Sodium + Sulfur → Na₂S

Note: For q, "Gallium + Chloride" — chloride is the ion, but gallium is the metal. So it's Ga³⁺ + 3Cl⁻ → GaCl₃

For o, since both are nonmetals, no ionic compound forms.

But if the worksheet expects a formula anyway, it might be SeCl₂, but that’s not ionic.

So best to state clearly.

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Summary of Answers:

| Letter | Elements | Compound Formed |
|--------|------------------------|-----------------|
| a | K + Cl | KCl |
| b | Mg + Br | MgBr₂ |
| c | Na + F | NaF |
| d | Na + Br | NaBr |
| e | Mg + Cl | MgCl₂ |
| f | Al + Br | AlBr₃ |
| g | Sr + I | SrI₂ |
| h | Na + O | Na₂O |
| i | Na + Cl | NaCl |
| j | Ca + F | CaF₂ |
| k | Al + Cl | AlCl₃ |
| l | K + I | KI |
| m | Mg + O | MgO |
| n | Rb + O | Rb₂O |
| o | Se + Cl | No ionic compound (SeCl₂ is covalent) |
| p | K + S | K₂S |
| q | Ga + Cl | GaCl₃ |
| r | Na + S | Na₂S |

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Explanation:

Ionic bonding occurs between metals and nonmetals. The metal loses electrons to form a cation, and the nonmetal gains electrons to form an anion. The charges must balance to form a neutral compound.

- Group 1 metals (Na, K, Rb): +1
- Group 2 metals (Mg, Ca, Sr): +2
- Aluminum, Gallium: +3
- Halogens (F, Cl, Br, I): -1
- Oxygen, Sulfur, Selenium: -2

For o, selenium and chlorine are both nonmetals, so they share electrons (covalent bonding), not transfer them. Therefore, no ionic compound forms.

All other combinations involve a metal and a nonmetal, so ionic compounds form.

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✔ Final Answer List:

a. KCl
b. MgBr₂
c. NaF
d. NaBr
e. MgCl₂
f. AlBr₃
g. SrI₂
h. Na₂O
i. NaCl
j. CaF₂
k. AlCl₃
l. KI
m. MgO
n. Rb₂O
o. No ionic compound
p. K₂S
q. GaCl₃
r. Na₂S

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