Question

Classify each substance as an element, a compound, a homogeneous mixture, or a heterogeneous mixture. Convert 7.93 times 10^-3 m to the equivalent length in nanometers

Answer 1

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Answer:

a) Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: helium

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water

Heterogeneous mixtures  : It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium. Example: Air

Homogeneous mixtures  : It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different.There is no physical boundary between the dispersed phase and dispersion medium. Example: salt in water

b) $7.93\times 10^{-3}m$ =? nm

$1m=10^9nm$

$7.93\times 10^{-3}m=\frac{10^9}{1}\times 7.93\times 10^{-3}nm=7.93\times 10^{-6}nm$

Thus $7.93\times 10^{-3}m=7.93\times 10{-6}nm$