270 likes | 608 Views
Grade 7 Science. Homogeneous & Heterogeneous Mixtures. Homogeneous Mixture. also called solutions can be solid, liquid or gas. Stainless steel. the particles are evenly mixed so that none of the original substances are visible. Kool-aid. they appear to be ONE substance
E N D
Grade 7 Science Homogeneous & Heterogeneous Mixtures
Homogeneous Mixture • also called solutions • can be solid, liquid or gas Stainless steel
the particles are evenly mixed so that none of the original substances are visible Kool-aid
they appear to be ONE substance • light passes through unaffected
Heterogeneous Mixtures • also called mechanical mixtures • can be solid, liquid or gas Granola bar
the different parts are visible to the eye (may need a microscope) • the particles do not evenly mix Concrete
Light will reflect perpendicular to the direction of the beam
Student Activity... • Create a chart and list the various homogeneous and heterogeneous mixtures in your home. • Share with your shoulder partner and add to your list.
The Tyndall Effect • A phenomenon that can be used to distinguish between solutions and what appears to be a solution • cannot be used to distinguish between a solution and a pure liquid
In a Solution... • Light passes unaffected (if a student looks at the beaker perpendicular to the direction of the beam they will NOT see it
In a Mechanical Mixture... • The light will scatter as it passes through the mixture because all particles are not dissolved (as shown on the left)
Both Hetero and Homogenoeus Mixtures? Complete Activity 7-1C Page 238 & 239
Post Activity Discussion... Enrichment