The electrostatic attraction between oppositely charged ions
A shared pair of electrons
Attraction between nuclei
A sea of delocalised electrons
Tap an answer to check it.
WhyIonic bonding is the electrostatic attraction between oppositely charged ions, formed when electrons are transferred from a metal to a non-metal.
2Multiple choice · Easy
What is the formula of magnesium chloride?
$\text{MgCl}$
$\text{MgCl}_{2}$
$\text{Mg}_{2}\text{Cl}$
$\text{MgCl}_{3}$
Tap an answer to check it.
Why$\text{Mg}^{2+}$ and $\text{Cl}^{-}$ combine in a $1:2$ ratio to balance charge, giving $\text{MgCl}_{2}$.
3Multiple choice · Medium
Ionic compounds conduct electricity when:
Molten or in aqueous solution
Solid only
Never
Only as a gas
Tap an answer to check it.
WhyIons must be free to move to conduct. In the solid lattice they are fixed, but when molten or dissolved in water the ions become mobile and conduct electricity.
4Multiple choice · Medium
What is the formula of aluminium oxide?
$\text{AlO}$
$\text{Al}_{2}\text{O}_{3}$
$\text{Al}_{3}\text{O}_{2}$
$\text{AlO}_{3}$
Tap an answer to check it.
Why$\text{Al}^{3+}$ and $\text{O}^{2-}$ combine in a $2:3$ ratio to balance the charges, giving $\text{Al}_{2}\text{O}_{3}$.
5Multiple choice · Medium
What is the formula of calcium nitrate?
$\text{CaNO}_{3}$
$\text{Ca(NO}_{3})_{2}$
$\text{Ca}_{2}\text{NO}_{3}$
$\text{Ca(NO}_{2})_{3}$
Tap an answer to check it.
Why$\text{Ca}^{2+}$ needs two $\text{NO}_{3}^{-}$ ions to balance charge, giving $\text{Ca(NO}_{3})_{2}$.
6Multiple choice · Hard
Which compound has the highest melting point?
$\text{NaF}$
$\text{NaCl}$
$\text{NaBr}$
$\text{NaI}$
Tap an answer to check it.
WhyLattice strength increases as ionic radius decreases. $\text{F}^{-}$ is the smallest halide ion, so $\text{NaF}$ has the strongest lattice and the highest melting point.
7Fill in the blank · Easy
The charge on an aluminium ion is (give sign and number, e.g. 2+).
Answer:
3+ / +3
WhyAluminium is in group 13 and loses 3 electrons to achieve a noble-gas configuration, forming $\text{Al}^{3+}$.
8Fill in the blank · Medium
The ionic compound formed from $\text{NH}_{4}^{+}$ and $\text{SO}_{4}^{2-}$ has the formula .
Answer:
(NH4)2SO4 / (NH_{4})_{2}SO_{4}
WhyTwo ammonium ions balance one sulfate ion: $(\text{NH}_{4})_{2}\text{SO}_{4}$ (ammonium sulfate).
9Multiple choice · Medium
Ionic compounds typically have high melting points because:
Strong electrostatic attractions hold the lattice together
They contain delocalised electrons
They consist of discrete molecules
They have weak London forces
Tap an answer to check it.
WhyStrong electrostatic attractions in the ionic lattice require a large amount of energy to overcome.
10Multiple choice · Hard
Which compound would be expected to have the highest lattice strength (and melting point)?
MgO
NaCl
KBr
NaI
Tap an answer to check it.
WhyHigher ionic charges and smaller ions give stronger attraction; MgO (2+ and 2-) exceeds NaCl (1+ and 1-).
Ready to test yourself?
Practise The ionic model with instant marking and per-topic score tracking.