Mahi Tuatahi / Do Now 🔗
- Complete another element quiz!
- You can move onto the next question set if you score 30/30 two days in a row!
- Record your score on your scoresheet
Ions 🔗
Ions are atoms that have gained or lost electrons in order to have a full valence shell.
Valence: outermost
Example 🔗
This is an oxygen atom. Copy the diagram into your book and give the electron shell configuration e.g. [2,3]
Making an ion is like rounding:
- Atoms with a less than half-full valence shell will perfer to lose electrons
- Atoms with a more than half-full valence shell will prefer to gain electrons
Think again about the oxygen atom and answer these questions:
- Will it prefer to gain or lose electrons?
- How many electrons will it need to gain/lose to have a full outer shell?
Copy this table into your own book and work in pairs to complete it.
| Oxygen Atom | Oxygen Ion | |
|---|---|---|
| Electron Shell Configuration | ||
| Number of Protons | ||
| Number of Electrons | ||
| Overall Charge |
| Oxygen Atom | Oxygen Ion | |
|---|---|---|
| Electron Shell Configuration | [2, 6] | [2, 8]2- |
| Number of Protons | 8 | 8 |
| Number of Electrons | 8 | 10 |
| Overall Charge | 0 | 2- |
Writing Ions 🔗
- Writing ions comes in two parts: the element, and the charge.
- The charge goes in a superscript like this.
- The number goes before the charge.
$$ \begin{aligned} O^{2-} \end{aligned} $$
Making Ionic Compounds 🔗
- To make ionic compounds we need the numbers in the superscript to balance to zero.
- To use more than one of an ion you use a subscript like this
$$ \begin{aligned} Na^{+} + Cl^{-} &\rightarrow NaCl \newline Cu^{2+} + 2OH^{-} &\rightarrow Cu(OH)_{2} \end{aligned} $$
Electron Transfer 🔗
Ionic compounds form because:
- some atoms want to give away electrons to get a full valence shell (become positive)
- some atoms want to receive electrons to get a full valence shell (become negative)
By giving/receiving electrons they form an ion becoming positive or negatively charged. Once they have a charge they are elecrostatically attracted together and make a neutral compound.
Mahi Tuatahi 🔗
Quiz! If you have scored 30 twice in a row with the elements you can try and ions quiz today!
Tākaro / Game! 🔗
- Form into your table groups/pairs with a whiteboard. We are going to make some ionic compounds. Most points wins!
Your answer is simply to give the compound like this: $NaOH$ has 1x $Na^{+}$, 1x $OH^{-}$.
🔗
Whakatika 🔗
| 1-5 | 6-10 | 11-15 |
|---|---|---|
| $NaI$ | $PbSO_{4}$ | $Al_{2}(SO_{4})_{3}$ |
| $AgI$ | $BaCO_{3}$ | $FeO$ |
| $LiF$ | $ZnI_{2}$ | $Fe_{2}O_{3}$ |
| $NHCl_{3}$ | $AlCl_{3}$ | $NaHCO_{3}$ |
| $MgO$ | $Al(NO_{3})_{3}$ | $Pb(HCO_{3})_{2}$ |