Available Answers

1. 1.

   Multiple-Choice Questions

   Tick (√) the correct option:

   1. The total number of elements known to us are:
      1. 110
      2. 116
      3. 120
      4. 118
   2. Which of the following is a metal?
      1. Arsenic
      2. Aluminium
      3. Germanium
      4. Silicon
   3. Non-metals exist as
      1. Solid
      2. Liquid
      3. Gas
      4. All of these
   4. Silver, gold and platinum are
      1. Noble metals
      2. Metals
      3. Non-metals
      4. Inert gases
   5. Which of the following metals is used for food packaging?
      1. Iron
      2. Sodium
      3. Silver
      4. Magnesium
   6. The property by which metals can be drawn into wires is called
      1. Malleability
      2. Ductility
      3. Conductivity
      4. Sonority
   7. Metals react with dilute acids to form salt and
      1. Oxygen
      2. Nitrogen
      3. Hydrogen
      4. Water
   8. Which of the following is a non-metal that exists in liquid state?
      1. Oxygen
      2. Sulphur
      3. Bromine
      4. Chlorine
   9. Which of the following is used for making pencil lead?
      1. Diamond
      2. Phosphorus
      3. Silicon
      4. Graphite
   10. Which of the following is a metal that can be cut with a knife?
       1. Sodium
       2. Lithium
       3. Magnesium
       4. None of these
   11. Which of the following non-metals is lustrous?
       1. Graphite
       2. Iodine
       3. Sulphur
       4. Both a and b
   12. Which of the following metals is used for making filament of an incandescent bulb?
       1. Sodium
       2. Tungsten
       3. Gold
       4. All of these
   13. A more reactive metal displaces less reactive metal from its salt solution. This is called
       1. Combination reaction
       2. Decomposition reaction
       3. Displacement reaction
       4. None of these
   14. Liquid hydrogen is used
       1. As a rocket fuel
       2. In welding metals
       3. In manufacture of fertilisers
       4. To make antiseptic creams
   15. The smallest unit of an element is
       1. Molecule
       2. Atom
       3. Particles
       4. Electrons
2. 2.

   Fill in the blanks:

   1. The most reactive metal is placed on the _________ and the least reactive metal at the _________ of the reactivity series.
   2. Mg + _________ → Mg (OH)₂ + H₂
   3. Graphite and iodine have _________ and _________.
   4. 4Fe + H₂O + O₂ → _________.
   5. Metals react with dilute acids and liberate _________.
3. 3.

   Tick (√) the correct and cross (X) the wrong statement:

   1. Aluminium is more reactive than zinc.
   2. Copper does not-get corroded.
   3. All ores are minerals, but all minerals are not ores.
   4. Metal surfaces should be repainted time to time.
   5. Non-metals combine with oxygen to form basic oxides.
   6. Magnesium forms black colour powder of magnesium oxide.
   7. The reactivity of all metals is not the same.
   8. Electric wires are made of iron.
4. 4.

   Match the following:

   Column A	Column B
   1. Acidic oxides	(a) 'Pop' sound
   2. Basic oxides	(b) Magnesium oxide
   3. Iron	(c) Yellow in colour
   4. Hydrogen	(d) Non-metals
   5. White powder	(e) Gold
   6. Sulphur	(f) Violet
   7. Rust	(g) Liquid state
   8. Malleable	(h) Metals
   9. Iodine	(i) Hydrated iron oxide
   10. Bromine	(j) Corrosion

    

5. 5.

   Find the odd one out:

   1. Gold, silver, graphite and platinum.
   2. Sulphur, diamond, graphite and iodine.
   3. Iron, mercury, brass, gold and diamond.
6. 6.

   Name the metals that are found in liquid state at room temperature.