Question

Q1-define the terms element, compound and mixture with the help of suitable examples.
Q2-among the following substances choose the element,mixture and compounds:
a) air
b) sand
c) diamond
d) brass
Q3-water in a stream after rain contains air bubbles, salt, calcium carbonate, sand grains, straw pieces and unfilterable clay particles. select from amongst these one example of each of a solvent, a solute, a suspension and a colloid.
Q4-a compound A changes directly from solid to gaseous state on heating with the help of a labelled diagram describe the process used for the separation of component A from NaCl.
Q5-suggest a way to determine whether a colourless liquid is pure water or a solution of salt or sugar in water, without tasting the liquid.

Answer 1

Q2.
mixture=air,sand,diamond.
compound=sand as SiO2,brass.
element=no elements.