Noble gases
Introduced| English | Meaning |
|---|---|
| noble gases/ˈnəʊbl ˈɡæsɪz/ | Elements with full outer electron shells, labelled Group 0 in this course or Group 18 in modern IUPAC numbering. |
| inert/ɪˈnɜːt/ | Not readily reacting under the conditions being considered. |
| full outer shell/fʊl ˈaʊtə ʃel/ | full outer shell |
| monatomic/ˌmɒnəˈtɒmɪk/ | Consisting of individual atoms rather than molecules containing several atoms. |
The unreactive Group 0
- At the far right of the table sits a group that barely reacts at all.
- These are the noble gases 稀有气体 (Group 0), famous for being inert 惰性.
Noble gas lab
Classify noble gas uses by the property that makes them useful.
Noble gases are unreactive because they have:
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A full outer shell is very stable.
Other elements react in order to reach a full, stable outer shell like the noble gases.
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A full shell is the stable arrangement elements aim for.
The noble gases are found in Group ______ of the Periodic Table.
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Group 0 (sometimes called Group VIII).
Why they are unreactive
- Noble gases have a full outer shell 满外层 of electrons.
- A full shell is very stable, so they have no need to gain, lose or share electrons.
The noble gases (Group 0) fill the far-right column of the periodic table
Noble gases exist as:
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They do not bond, so they are monatomic.
Properties
- They are colourless gases that exist as single atoms (monatomic 单原子).
- They are non-flammable and chemically very unreactive.
Helium is used in balloons because it is:
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Low density lifts; inertness makes it safe.
Uses
- Helium is used in balloons and airships (less dense than air, non-flammable).
- Argon fills light bulbs; neon glows in signs — uses that rely on their inertness.
A full outer shell means stability. The noble gases are unreactive precisely because their outer shell is already full. Other elements react in order to reach this same stable arrangement.
You've got it
- noble gases (Group 0) have a full outer shell, so they are inert (unreactive)
- they are colourless, monatomic gases
- uses rely on inertness: helium (balloons), argon (bulbs), neon (signs)
Write from boiling point rising down the group
- Helium, neon and argon are noble gases.
- Their atoms have full outer shells and they exist as single atoms.
How does boiling point change from helium to argon?
Stronger forces between larger atoms raise the boiling point.
How do noble-gas boiling points change down the group?
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Larger atoms are attracted to each other more strongly.