Teacher-made Learner’s Home Task
School: Pilar National High School Date: September 15, 2020
Grade/Section: Grade 7-Aguinaldo, Macapagal Subject Area/s: Science 7
I. MELC: Investigate properties of saturated and unsaturated solutions S7MT-If-5
II. Objective/s:
a. Knowledge: identify solution, suspension and colloid mixtures based on
properties
b. Skills: create a Venn diagram that demonstrates the differences between
solutions, suspensions and colloids
c. Values/Attitude: appreciate the different mixtures used in daily life
III. Subject Matter: Homogeneous and Heterogeneous Mixtures
IV. References:
https://www.youtube.com/watch?v=XEAiLm2zuvc
https://www.thoughtco.com/solutions-suspensions-colloids-and-
dispersions-608177
https://www.thoughtco.com/definition-of-tyndall-effect-605756
IV. Procedure:
A. Readings
i. Review
A homogeneous mixture is a mixture in which the components that make
up the mixture are uniformly distributed throughout the mixture.
A heterogeneous mixture is a mixture in which the components of the
mixture are not uniform or have localized regions with different
properties.
ii. Key Points
It’s all about the particles!
The size of the particles has a great effect on the properties of a
mixture.
You must observe a mixture’s properties before deciding whether
it is heterogeneous or homogeneous.
Mixtures get classified as solutions, suspensions, or colloids
based on particle size.
Solutions
A solution is a homogeneous mixture of two or more components. When
substances dissolve and form a homogeneous mixture, the mixture is called a
solution. Whatever substance there is more of is called the solvent, while the
lesser substance is called the solute. The components of a solution are atoms,
ions, or molecules, making them 10-9 m or smaller in diameter.
Properties of a Solution:
They do not separate into layers over time.
If they are poured through a filter, none of
the substances will get trapped.
Light passes through them.
All of the particles in a solution are too small
to become separated, filter out, or scatter
light.
Example: Iced tea
Suspensions
The particles in suspensions are larger than those found in solutions.
Components of a suspension can be evenly distributed by mechanical means,
like by shaking the contents but the components will eventually settle out.
Properties of a Suspension:
Heterogeneous mixture
Separates into layers over time.
Filters can separate particles that make up a
suspension.
Particles are larger than those in a solution.
Scatter light. (This is known as the Tyndall
Effect)
Suspended particles settle out of a suspension.
Example: flour in water
Colloids
Particles intermediate in size between those found in solutions and
suspensions can be mixed in such a way that they remain evenly distributed
without settling out. These particles range in size from 10-8 to 10-6 m in size
and are termed colloidal particles or colloids. The mixture they form is called a
colloidal dispersion. A colloidal dispersion consists of colloids in a dispersing
medium.
Properties of Colloids:
Do not separate into layers.
Particles will not become trapped by a filter.
Scatter light.
Colloids and suspensions appear cloudy; unlike
solutions which are much clearer.
Colloids and solutions will not separate into layers;
suspensions will.
Example: Milk
Telling Them Apart
You can tell suspensions from colloids and solutions because the
components of suspensions will eventually separate. Colloids can be
distinguished from solutions using the Tyndall effect. A beam of light passing
through a true solution, such as air, is not visible. Light passing through a
colloidal dispersion, such as smoky or foggy air, will be reflected by the larger
particles and the light beam will be visible.
The Tyndall effect is the scattering of
light as a light beam passes through a colloid.
The individual suspension particles scatter
and reflect light, making the beam visible.
The Tyndall effect was first described by
19th-century physicist John Tyndall.
The amount of scattering depends on the
frequency of the light and density of the
particles. As with Rayleigh scattering, blue
light is scattered more strongly than red light by the Tyndall effect. Another way
to look at it is that longer wavelength light is transmitted, while shorter-
wavelength light is reflected by scattering.
The size of the particles is what distinguishes a colloid from a true solution.
For a mixture to be a colloid, the particles must be in the range of 1-1000
nanometers in diameter.
B. Exercises for skill subjects/Analysis questions using HOTS for
content subjects
i. Exercise 1: Classify each of the following as a heterogeneous mixture or a
homogeneous mixture.
ii. Exercise 2
Directions: Answer briefly the questions below.
1. In what type of mixture is to easiest to separate the component
substance? Why?
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2. Not all solutions are solids dissolved in liquids. Provide two examples of
other types of solutions.
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3. Given an unknown mixture consisting of two substances, explain how a
scientist could use lab techniques to determine whether the mixture is a
true solution, a colloid, or a suspension.
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C. Assessment/Application
Directions: Fill-out the Venn diagram below using the properties of solutions,
suspensions and colloids.
Prepared by:
CARISSA MAE T. CAÑETE
Teacher
Verified by:
ROQUE L. BORINAGA
School Head
