When we burn a cleaned piece of magnesium ribbon in air, we observe :
a white dazzling light while burning
a white residue left after burning
a black residue left after burning
(1) and (2)
It has silvery-grey or golden-yellow colour.
Metals
Non-metals
Semi-metals
Metalloids
While heating a mixture of ammonium chloride and sodium chloride, it is advised to keep your face away from the apparatus because :
ammonium chloride vapours may cause irritation to eyes and nose
sodium chloride vapours may cause irritation to eyes
chlorine vapour may cause irritation to eyes
ammonium vapours may block nose
Some elements have intermediate properties between those of metals and non-metals, they are called
Ores
Sponge is an example of
Gel
Sol
Foam
Emulsion
Immiscible liquids separate out in layers depending on their densities.The principle of this is
Centrifugation
Separating funnel
Evaporation
Condensation
A substance composed of two or more elements, chemically combined with one another in a fixed proportion is
Compound
Complex
Mixture
