Vidaara.orgClass 10 · Chemistry
CodeVID-C10-03-T1-01
Assignment — Properties of Metals & Non-metals
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Write balanced chemical equations wherever asked. Only final answers are given at the end — for full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
Which property allows metals to be drawn into wires?
- A.malleability
- B.ductility
- C.sonority
- D.lustre
2.
The non-metal that is lustrous is:
- A.sulphur
- B.iodine
- C.carbon (coal)
- D.phosphorus
3.
Which oxide is amphoteric?
- A.Na₂O
- B.CO₂
- C.ZnO
- D.SO₂
4.
Iron reacts with which form of water?
- A.cold water
- B.hot water
- C.steam
- D.it does not react
5.
Which metals are soft enough to be cut with a knife?
- A.iron and copper
- B.sodium and potassium
- C.gold and silver
- D.zinc and lead
Section B — Short Answer (2 marks)
3 × 2 = 6 marks
6.
Define malleability and ductility with one example each.
7.
Write the balanced equation for the reaction of potassium with cold water.
8.
Why are food cans coated with tin and not with zinc?
Section C — Short Answer (3 marks)
2 × 3 = 6 marks
9.
Show that Al2O3 is amphoteric by writing its reactions with HCl and with NaOH.
10.
List any three physical properties in which metals differ from non-metals.
Section D — Long Answer (5 marks)
1 × 5 = 5 marks
11.
Describe the reaction of metals with oxygen, water and dilute acids with one balanced equation in each case, and explain why non-metals behave differently with acids.
Answer Key
Section A — Multiple Choice Questions
- (B) ductility
- (B) iodine
- (C) ZnO
- (C) steam
- (B) sodium and potassium
Section B — Short Answer (2 marks)
- Malleability is the ability to be beaten into thin sheets (e.g. gold, aluminium foil); ductility is the ability to be drawn into thin wires (e.g. copper, silver).
- 2K + 2H₂O → 2KOH + H₂ (the reaction is highly exothermic and the hydrogen catches fire).
- Tin is less reactive than zinc and is non-toxic, so it does not react with food; zinc is more reactive and could react with the food.
Section C — Short Answer (3 marks)
- With acid: Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O. With base: Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O. Reacting with both an acid and a base proves it is amphoteric.
- Metals are lustrous, malleable/ductile, sonorous and good conductors; non-metals are dull, brittle, non-sonorous and poor conductors (exceptions exist such as iodine and graphite).
Section D — Long Answer (5 marks)
- Oxygen: metals form basic/amphoteric oxides, e.g. 4Al + 3O₂ → 2Al₂O₃. Water: reactive metals displace hydrogen, e.g. 2Na + 2H₂O → 2NaOH + H₂ (Mg with hot water, Fe with steam). Dilute acids: metals above hydrogen displace H₂, e.g. Zn + 2HCl → ZnCl₂ + H₂. Non-metals do not displace hydrogen from acids because displacing hydrogen needs the element to donate electrons to H⁺, but non-metals tend to gain electrons rather than lose them.
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