Matter In Our Surroundings-Important Questions

HIGHER ORDER THINKING QUESTIONS
Matter in Our Surroundings
1.  Which of the following is heaviest metal?
      Pb, As, Al, Ni
2.  Which of the following has highest melting point?
      Ni, Fe, Pt, W.
3.  Which property of cotton makes it suitable for use as clothing in summer?
4.  Name the synthetic fibre which resembles wool in its properties.
5.  Which material is used for making CDs?
6.  Why is rayon called artificial silk?
7.  What is used for coating non-stick kitchen wares?
8.  Which gas is used as referigerant in fridge and in air conditioner?
9.  Why do gold, silver and platinum occur in free state?
Answers.
1.  Pb
2.  W
3.  It absorbs moisture
4.  Acrylic
5.  Polycarbonate
6.  It is prepared from cotton but has shine like silk
7.  Teflon
8.  Freon
9.  Freon