1) When salt is mixed into water it becomes a. element b. compound c. mixture d. solute
|
||||
2) Alloys include a. steel b. brass c. bronze d. all of them
|
||||
3) The point at which solid substance changes into liquid state, is called a. melting point b. boiling point c. power point d. complex point
|
||||
4) The techniques which help to separate mixtures, involve a. filtration b. distillation c. chromatography d. all of them
|
||||
5) In clean air, percentage of oxygen is a. 0.07 b. 0.1 c. 0.15 d. 0.17
|
||||
6) A technique which is used to desalinate water, is a. reverse osmosis b. distillation c. filtration d. heating
|
||||
7) Balloons are filled with a. carbon dioxide b. oxygen c. helium d. nitrogen
|
||||
8) Nitrogen helps in preparation of nitrogen based a. plants b. fertilizers c. seeds d. trees
|
||||
9) For purification water is passed through a. sand b. colander c. watch glass d. strainer
|
||||
10) The percentage of noble gases in air is a. 0.2095 b. 0.78 c. 0.009 d. 0.0003
|