Practice Flashcards
Flip to reveal answersWhat is an alloy?
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 12 Flashcards — Alloys and polymers
Sign up free to track progress and get spaced-repetition review schedules.
Question
What is an alloy?
Answer
A **mixture** of a metal with one or more other elements (it is **not** a compound — no fixed ratio).
Question
Why is an alloy harder than a pure metal?
Answer
Its **different-sized atoms disrupt the regular layers**, so the layers **cannot slide** over each other as easily.
Question
Do alloys still conduct electricity?
Answer
Yes — they keep **metallic bonding** (a sea of delocalised electrons); they are just **harder** than the pure metal.
Question
Name two everyday alloys and their metals.
Answer
**Brass** = copper + zinc; **steel** = iron + carbon (also bronze = copper + tin).
Question
What is a monomer?
Answer
A **small molecule** that joins to many others to form a **polymer** (a giant molecule).
Question
What is an addition polymer?
Answer
A long-chain molecule made by joining many **alkene monomers** (with **C=C**), with **no atoms lost**.
Question
What happens to the C=C during addition polymerisation?
Answer
The **double bond opens up** — one bond becomes a single bond, the other joins to the next monomer.
Question
What is a repeating unit?
Answer
The part of the polymer chain that **repeats**; get it by **opening the C=C** and drawing a bond out of each end.
Question
Monomer vs repeat unit?
Answer
**Monomer** has the **C=C double bond**; **repeat unit** has a **single** C–C bond with a bond out of each end.
Question
How do you find the monomer from a polymer?
Answer
Take **one repeating unit** and **put the C=C double bond back** between the two carbons.
Question
Monomer of poly(ethene)?
Answer
**Ethene, CH_{2}=CH_{2}** — the repeat unit is –CH_{2}–CH_{2}–.
Question
Why is poly(ethene) a useful material?
Answer
It is **chemically unreactive (inert)** and waterproof, so it resists corrosion — useful for packaging and containers.
Read the notes
Full study notes for Alloys and polymers
Topic 2.4 hub
From models to materials
More from Topic 2.4
All flashcards in this topic
Chemistry exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free