What is a colloid?

Answer 1

A type of solution of intermediate sized particles suspended and completely dispersed in another substance. Because the particles are not completely dissolved (although dispersed), it may or may not be a homogeneous mixture. Depending on the size of particles, the solution can be either; particles that are less than 10-9 m are homogeneous mixtures, particles that are 10-9- 10-6 m are colloids, and particles that are greater than 10-6 m are heterogeneous mixtures.

Colloids also exhibit the Tyndall effect, in which a beam of light is visible from the side, yet still passes through the solution. (You can see lasers through a mist or fog.)

Classifications:

• Aerosol (liquid disbursed in a gas - fog)
• Foam (gas disbursed in a liquid - shaving cream)
• Solid Foam (gas disbursed in a solid - Styrofoam)
• Emulsion (liquid disbursed in a liquid - butter)
• Gel (liquid disbursed in a solid - jello)
• Solid Aerosol (solid disbursed in a gas - smoke)
• Sol (solid disbursed in a liquid - blood)
• Solid Sol (solid disbursed in a solid - alloy)

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Answer 2

A colloid is a state of matter in between solid and liquid. It's easy to imagine; a colloid is kinda like a mushy solid that will take the shape of it's container if it's forced. Some colloids include butter, glue, ice cream, tar, jelly, Jell-O, geletin, and jam.