BETAPlatform ini sedang dikembangkan aktif; bug, fitur yang belum ada, dan risiko kehilangan data mungkin terjadi. Terima kasih atas dukunganmu!

Properties Uses And Alloys Of Metals

Belajar sambil bermain

Jawab soal-soal ini untuk dapat energi, lalu memancing dan menjelajah. Tanpa akun.

Untuk guru: slide pelajaran, catatan ulasan siap pakai untuk Properties Uses And Alloys Of Metals (Co-ordinated Sciences (Double Award) [CIE], Chemistry) — gunakan dalam pelajaranmu, atau jalankan topik sebagai aktivitas kelas interaktif yang dimainkan murid sebagai permainan langsung.

Catatan pelajaran

Physical Properties of Metals

  • Metals conduct heat and electricity due to delocalised electrons that move through the structure.
  • They are malleable (can be hammered into shapes) and ductile (can be drawn into wires) because layers of positive ions can slide over each other.
  • Metals generally have high melting and boiling points because of strong electrostatic attraction (metallic bonds) between positive ions and delocalised electrons.

Metallic bonding in aluminium

Aluminium — metallic bondinge⁻e⁻e⁻e⁻e⁻e⁻e⁻e⁻e⁻Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Al³⁺Aluminium ionSea ofdelocalisedelectronsLayers slideover eachother

Chemical Properties of Metals

  • Metals react with water (cold or steam) to produce a metal hydroxide or oxide plus hydrogen gas.
  • Example with cold water: Ca + 2H₂O → Ca(OH)₂ + H₂.
  • Example with steam: Zn + H₂O → ZnO + H₂.
  • Metals react with acids to produce a salt and hydrogen: metal + acid → salt + hydrogen.
  • Example: Fe + 2HCl → FeCl₂ + H₂.

Uses of Aluminium

  • Aluminium has low density and is resistant to corrosion due to a protective oxide layer.
  • Used in aeroplane bodies because of high strength-to-weight ratio.
  • Used in overhead power cables because it is a good electrical conductor and has low density.
  • Used in food cans because it is non-toxic and resistant to corrosion and acidic foods.

Uses of Copper

  • Copper is a very good electrical conductor and is ductile.
  • Used in electrical wiring due to high conductivity and ductility.
  • Used in pots and pans because it is a good heat conductor, unreactive, and malleable.
  • Used in water pipes because it is non-toxic, unreactive with water, and malleable.

Structure of an electrical cable

Structure of an electrical cable

Alloys – Composition and Properties

  • An alloy is a mixture of a metal with other elements (often other metals, sometimes non-metals).
  • Brass (copper + zinc) is much stronger than either metal; used in musical instruments, ornaments, door knobs.
  • Stainless steel (iron + chromium, nickel, carbon) is hard and resistant to corrosion/rusting; used in cutlery.
  • Other alloys: iron with tungsten (extremely hard, heat resistant); aluminium with copper, manganese, silicon (strong, low density for aircraft).
  • Alloys are not compounds – they are mixtures, not chemically combined.

Structure of Alloys (Extended Tier)

  • Pure metals have a regular arrangement of positive ions in layers.
  • Alloys contain atoms of different sizes, which distort the regular lattice.
  • The distortion makes it harder for layers to slide over each other, so alloys are usually harder/stronger than pure metals.

Structure of an alloy

Structure of an alloy

Slide

Sign up free to view the lesson slides

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

Soal latihan

Pratinjau gratis — 8 dari 56 soal. Daftar untuk melihat semuanya.
  1. 1.State two physical properties of metals.

    Easy
  2. 2.State two uses of aluminium.

    Easy
  3. 3.State two uses of copper.

    Easy
  4. 4.What is an alloy?

    Easy
  5. 5.State two examples of alloys and their uses.

    Easy
  6. 6.Explain why alloys are usually harder than pure metals.

    Medium
  7. 7.Which property makes aluminium suitable for making aeroplane bodies?

    Easy
    • Ahigh density
    • Blow density
    • Chigh reactivity
    • Dpoor conductor of electricity
  8. 8.Which of the following is an alloy?

    Easy
    • Apure copper
    • Bpure iron
    • Cbrass
    • Daluminium

Unlock all 56 questions, flashcards & more

Buat akun gratis untuk melihat setiap soal, slide, kartu flash, dan catatan ulasan topik ini.

Soal ujian lampau

Latihan soal ujian lampau untuk topik ini segera hadir.
Segera hadir