Is the number of elements likely to increase or decrease in the future? why so?
What is the most abundant element in our Earth's crust?
Why is carbon used as/for/in
(i) formation of living tissues?
(ii) as a fuel
(iii) pencil leads
Why is hydrogen used for:
(i) making margarine
(ii) as rocket fuel
(iii) for filling weather balloons
Why is sulphur used
(i) for making insecticides
(ii) for making medicinal drugs
(iii) for hardening rubber used in making car tyres
Why is oxygen used for
(i) Respiration -why is it necessary? To which organ?
(ii) for combustion
(iii) in oxy-acetylene flames for weilding
Why is Nitrogen used
(i) for the formation of plant and animal proteins
(ii) in the manufacture of fertilisers
(iii) in the liquid agent as a cooling agent
Is a compound formed when iron rusts? If so, what is the compound formed and what are the reactants that form the compound?
2007-10-05
19:50:52
·
3 answers
·
asked by
Yuppy kid! =P Roxzzz....
2