Estimated timeframe
For each 40-45 minute science day, the number of days required for each part of each lesson is
typically:
Engaging scenario + focus question + prediction
Planning for experiment (drawing charts, writing vocab in glossary,
etc)
Experiment
Making meaning conference and claims and evidence
Conclusions and reflection
1-2 days
1 day
1-2 days
1-2 days
1 day
This should result in about the following timeframe for the unit:
Lesson 1
Lesson 2
Lesson 3
Lesson 4 (depending on how thoroughly phase changes are discussed)
Lesson 5
total
6 days
5 days
5 days
5-6 days
5 days
26-27 days
Introduction to chemistry and the Big Idea of this unit
Thank you so much for teaching the Mixtures and Solutions Unit. If you have any
corrections, feedback, comments, or questions about the unit, please do not hesitate to contact
me at rajameton@lcsc.edu.
In this note, I want to offer some background for the BIG IDEA and also the matter chart
that appears throughout the unit, which is duplicated on the next page. There is also a timeline
for the unit and a summary of the vocabulary for your wordwall.
So, here is the background for the BIG IDEA: At the heart of chemistry is the desire to
explain how matter behaves. Matter is the stuff around us with mass, and includes flowers,
people, furniture, cars, food, everthing. When chemists ask questions about matter, they must
be very specific about the type of matter that they are talking about. The questions that a
chemist asks about flowers are very different than the questions the chemist asks about a car!
Here are some examples of the sorts of questions that a chemist might want to find out about
different types of matter:

What causes flowers to have their specfic colors and fragrances?

How can we make plastics that are flexible yet strong?

Why are diamonds so hard?

Will a new pesticide hurt fish if it is released into the wate?r

Can a drug be made that better treats MRSA? Or cancer? Or the common cold? Or
heart disease?

How can we make ice colder so that we can make great ice cream?
The lists of questions are endless! Try taking an object, like your pen, and think of all the
questions that you could ask about its physical nature: Why is the plastic rigid? Can you melt
the plastic? What makes the ink black? What makes the ink impossible to erase? How is the
plastic given its shape? And the list goes on and on.
At the heart of how chemists explain all of these different properties is the notion of the
atom. An atom is a small unit of matter that comes in 115 different types called elements.
Most of the materials around us are composed of just a few elements: carbon, nitrogen,
hydrogen, oxygen and a little phosphorus, sulfur, sodium and magnesium. So how then, do we
get the incredible varied types of matter around us like stuffed animals, DNA, plastic bags,
crayons, chocolate chip cookies and water? It is because atoms combine in different ways to
give compounds.
Compounds, also called molecules, are specific arrangements of atoms. For example, a
water molecule is composed of two hydrogens and an oxygen. Compounds can be as small as
two atoms, up to many thousands of atoms in proteins and plastics. The matter that we can see
contains many, many molecules. Occasionally, the matter that we see is composed of one type
of molecule, and is called a pure compound. Most of the time, matter is a combination of
many different types of molecules, and these are mixtures.
You may notice that many of the terms that I used above (matter, elements, pure
compounds and mixtures) are shown in the figure below. I meant for that to happen! The
figure below shows how chemists boradly organize matter: we divide anything that we
encounter into mixtures or pure substances and then further subdivide it as shown below.
Much in the way that a biologist organizes living organisms into kingdoms and phyla, doing this
categorization helps chemists organize and describe the enormous amount of matter around us
and begin to describe some of its differences and similarities.
Pure substances (LE2 and LE3)
Solutions (LE2)
Mixtures (LE1)
Over the course of this unit, you will introduce your students to the terms in the chart
through specific examples of materials in their everyday life such as salt and water.
Furthermore, you and your students will explore similarities within these categories. All
mixtures, for example, can be separated. You will also investigate how different types of matter
within a single category can differ, leading to the BIG IDEA: “Elements and their combinations
account for all the varied types of matter around us.”
Unit Vocabulary (in order of appearance in each lesson)
Lesson
1
2
Term
Mixture
Solid
Liquid
Property
Pure Substance
A solution
Solvent
Solute
Evaporation
Crystal
3
4
Solid (repeated from 1)
Atom
Element
Freeze
Freezing point
Concentration
Saturated
Solubility
Phase change
5
Melt
Vaporize
Condense
No new vocab
Definition
a combination of materials
matter with definite shape and volume
matter with a definite shape but indefinite
volume
a characteristic feature
a single type of matter (an element or pure
compound)
a mixture of two or more different substances
where one substance dissolves in another.
The major component(s) of a solution
The minor component(s) of a solution
Change of state from a liquid to a gas
A solid material with a specific and repeating
pattern of atoms
matter with definite shape and volume
The smallest unit that makes up all matter
A type of atom
To change from a liquid to a solid (opposite of
melting)
the temperature at which a liquid freezes.
the amount of one compound in a mixture.
A solution with the maximum amount of a solute
dissolved in it.
Solubility: the amount of a solute in a saturated
solution.
When a solid, liquid or gas changes to a different
state of matter.
To change from a solid to a liquid.
To change from a liquid to a gas.
To change from a gas to a liquid.