Transcript What do you know about light?

Separating Mixtures
How can you Separate
Mixtures?
• A mechanical mixture has a
heterogeneous composition.
• Since the types of particles in the
mixture are not strongly attracted
to each other, they can be
separated by a number of different
ways.
Ways to Separate Mixtures
• Heterogeneous mixtures can be
separated in the following ways:
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Settling or Floating
Filtration
Magnetism
By hand
Dissolving and evaporating
Settling or Floating
• Settling or Floating: When mixtures
are separated into layers because of
their density (meaning some float
and some sink), we can separate
them by skimming, pumping, or
pouring off the layers.
Filtration
• Filtration: Different sized of filters
are available, ranging from filters
capable of capturing bacteria, to
those used to sieve gravel.
Magnetism
• Magnetism: Magnets can be used
to separate particles such as iron,
nickel or cobalt from non-magnetic
materials.
By Hand
• By Hand: Large particles that are
easily identifiable can be separated
by hand. For example, it would be
easy to separate pieces of Trail Mix.
Dissolving and Evaporating
• Dissolving and Evaporating:
Certain solvents can be used to
dissolve a solute and separate it
from a mixture. The solute can
then be recovered by evaporating
the solvent.
Separating Mixtures Questions
1. Explain which separating
techniques you might use to
separate the substances in each of
the mixtures:
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Water, sugar and sand
Water flour and marbles
Vegetable soup, salt and water
Water iron fillings and soil
Questions Continued…
2. Draw a flow chart to show hoe you
would separate a mixture of iron
fillings, sand, salt, stones, and
sawdust.
3. Explain why settling isn’t always
used to separate particles
suspended in a liquid?