Question

19. A purple –coloured non-metal forms a brown solution in alcohol which is applied on wounds
as an antiseptic. Name the non- metal.
20. State whether given statement is true / false :
i. The process of obtaining metal in its free state from its ore is called ‘Refining of ore “
ii. Aluminium is the most abundant metal in the earth’s crust.
iii. Iodine is the only metal which has lustre.
iv. Gold is the only metal that occurs in native state.
v. Silicon is the element that has properties of metals as well as non- metal.
21. Fill in the blanks :
i. Aluminium is extracted from _______ ore.
ii. The process of removal of impurities from the ore is called ________ .
iii. ________is a metal that exists in liquid state.
iv. A mineral is a naturally occurring ________ substance found deep under the surface
of earth.
v. ______ a form of carbon is the hardest substance.
22. One word answer :
1 Name the metal which exists in liquid state at room temperature.
2 Which metal is extracted from haematite ore?
3 Find the odd one out: Sulphur, nitrogen, oxygen, chlorine.
4 List any two physical properties of metal due to which it is used for making cooking
utensils.
5 What do you understand by the term ‘Malleability?
6 Write the composition of an alloy being used for making table ware .
23. Match the following
A. a)bauxite i)combined state of carbon
b)concentration of ore ii) free state of carbon
c) fullerenes iii) aluminium
d) bicarbonates iv)removal of impurities from ore
B. a)mercury i)good conductor of electricity
b) iodine ii)metal in liquid state
c) bromine iii) lustrous non-metal
d) graphite iv) non-metal in liquid state
C. a) gold i)electrical cables
b) copper ii)noble metals
c) aluminium iii)decorating food stuffs
d) silver iv )aircrafts body
D. a)stainless steel i)magnets
b) brass ii)automobile parts
c) duralumin iii) surgical implements
d)alnico iv) decorative statues.
E. a)gun powder i) diamond
b)antiseptic ii)sulphur
c) match box iii) iodine
d)cutting tools iv) phosphorus
24. Sneha was eating chocolate and while throwing the wrapper she thought out of curiosity
that will the wrapper act as a conductor of electricity or not . For this she made an electric
circuit and to her surprise the bulb started glowing when she placed the chocolate wrapper
in the circuit.
i) Name the metal used in making the wrapper of chocolate.
ii) Which property of this metal is responsible for converting it into wrapper?
iii) Mention any other application of this metal.
25. Riya went with her mother to a jewellery shop to purchase jewellery. Her mother asked the
jeweller to show them jewellery in pure gold and it should not be mixed with any other
thing.
i) Was Riya’s mother right for asking jewellery in pure gold? If no , give reason
ii) Which two metals are mixed with gold for making jewellery.

Answer 1

Answer:

19) alcohol

20)1235 are correct

21)1Bauxite,2)gauge,3)mercury,4)iron,5)diamond

24)No it will not act as conductor

25) No it is wrong the gold will mix with copper to form a ornament

Answer 2

Answer:

20. i the process of obtaining metal in it's free state