Summer's coming to a close and like other homeschoolers we are developing our plan for this school year. Instead of a science experiment this time, I thought now would be a good time to review the basic, yet necessary ingredients that are often missing from homeschool science.
Most homeschoolers believe that if they cover content, things like what's in the books, information, do a demonstration, that they've covered science. But the other half of the equation is a set of skills that must be mastered. One of those skills is learning to perform the steps of an experiment. When I say steps here, I'm not talking about the directions or procedure, but the scientific method. Many homeschoolers do a demonstration and call it an experiment. Or they'll do an experiment and say "oo, wow!" and be done with it. But what we need to do, is an experiment where we test something, making a hypothesis and then take measurements and data. We analyze the data and graph the results. Finally we write up our conclusion as to whether or not our hypothesis tested true. THOSE are the steps. So here's an activity where the main concern is learning to use the scientific method, not necessarily what you're testing.
Testing suds ability of dish soaps (expensive to store brands)
First, guess at which ones will have higher suds levels.
Perform test of each soap, one at a time:
Use empty single serving sized soda bottles (all the same size)
Measure equal drops of each soap into it's own soda bottle
Measure 2 cups water into each bottle.
Now shake for equal amounts of time, for all bottles.
Measure height of suds at end of shaking and again after 1 minute for each.
Record findings.
There are many ways to analyze this data, talking about hardness of water, shaking time, height of suds, given more time, how many suds remain, etc. The important thing is that our children are learning the "science" in science.
Here's the steps again:
Hypothesize what you think the results will be
Perform the test with accuracy, taking care to do the same to all items so you can rule out variables that will ruin your results.
Take data/measurements
Analyze data/ graph results
Discuss/conclusions/what-if's
Once our babies get a good idea of how experimentation works, we can move on to more advanced experiments. Of course these skills also transfer across the curriculum into math skills and writing skills as well
Acid, Base, Neutral
One of the most basic concepts in
science is whether substances are acidic, basic or neutral. This can be a
pretty abstract concept for children so the sooner we can approach this
topic with them the better. Many of you may have already begun this with
your children using cabbage juice. But for those of you who don’t
understand let me take a moment to explain. Most of you know that things
can be acidic. The opposite of acidic is alkaline. We sometimes call it
basic. We have a scale to measure acidity and alkalinity (basicity) of
substances. We call it the pH scale. (Just as a factoid, it gets it’s
name from “proton of Hydrogen”).
The pH scale ranges from 1 to 14 with neutral being the middle 7.
Acids are the lower numbers and bases are the higher numbers. This scale
sometimes confuses people because acid seems like a really strong thing
while basic seems weak. So people think acids should be higher. This is a
common problem. In reality, both ends of the scale are strong, capable of
extreme damage on the wrong surfaces and cause strong chemical reactions.
The kinder gentler part of the scale is in the middle or neutral. When I
was first learning this concept I pictured a scale like a thermometer,
dipping into an acid, the lower I went on the scale closer I got to the
acid. Acids and bases have some characteristics that scientists use to
classify them.
Bases
Bases range on the pH scale from 7.1
to 14. In the 8 to 9 , mild range they are good soaps for our skin Bases
are slippery feeling. Bases have a bitter taste. Strong bases are also
potentially harmful. Bleach is a strong base, so is ammonia. Strong bases
cause skin burns but most people don’t realize it at first. The burn
takes a little while to be felt. Strong bases give off noxious fumes that
are harmful and can even be fatal.
Acids
Acids range on the pH scale from 6.9
to 1. Acids tend to break substances down so they are often used to clean
metals or to dissolve them. Acids taste sour. The citrus fruits are acidic
and have citric acid in them. Think lemon, very acidic. Sodas have
carbonic acid in them, so not all acids are harmful, just like not all
bases are. It depends on their number on the pH scale.
Neutral
Neutral substances have a pH of 7. The
closer you get to 7, the less harmful a substance is to our tissues. Our
bodies have an average pH of 7, give or take a decimal on either side.
Some parts of our bodies are lower pH, like in our saliva. Our stomachs
are very low in pH and host several very strong acids. Substances like
water and milk are a pH of 7.
There are many things to teach our
babies about this scale. We can start small with the information above
with our kids who are ready for this. The younger ones will still enjoy
watching and helping to test these substances even if they don’t really
understand yet.
Scientists use pH paper or litmus
paper to test the pH of substances. You can order litmus paper from any
science supply company. Home Training Tools has it here for a couple of
bucks:
http://www.hometrainingtools.com/catalog/psearch?q=litmus+paper&t=p
You’ll
have to make sure you buy broad range paper that tests 1- 14.
Any lab you do must be testable, where
you gather data and make comparisons. Simply testing stuff and saying
“cool” isn’t real science although it is fun. To teach our babies
the science in it, we use a lab report and set up an experiment with a
hypothesis and data and conclusions.
I have created a lab report for you
and you can get it here:
Lab
Report
In this lab you will test different
substances to determine whether they are acids and bases and how strong of
an acid or base they are. So your children would predict this information
before testing anything. To get an idea of what to guess, inform them that
strong acids like sulfuric acid or hydrochloric acid tests at .1
(point one) and stomach acids are between 1 and 3. And Lye (drain opener)
is 12 to 14.
My suggestions for substances to test
are:
Ketchup
Soda
Milk
Lemon juice
Bleach
Water
Liquid dish soap mixed with a little
water
Brewed coffee
Hot sauce
Ammonia
Milk of Magnesia
Raw eggs
Grapes
Saliva
After predictions, test each substance
and place data in the table. The rest of the process is to analyze your
data and draw conclusions and that’s what the suggested questions on the
lab report will lead your children to do.
An outdoors science problem
solver
This
activity comes from my workshop but I like it so much I wanted to share
it. This isn’t mine, it’s pretty standard in all basic high school
chemistry classes as an introduction activity.
Problem
solving is a key skill in science. This activity is fun to solve and can
be a work in progress over several days if need be. It also teaches some
properties of chemistry.
You will need to purchase
iron shavings.I found some at this web site:
http://www.physlink.com/estore/cart/IronFilings.cfm
for $2.
In a large container, mix water, sand, lots of salt
and the iron shavings.
The problem
posed to your little scientists is how to separate them.
If you pour the water
out, you loose the salt. If you separate them you’ll now have a
salt-water mixture and a sand and iron mixture.
Have your
child work their way through this in their mind and verbally with you
before they jump in. Guide them along by asking then saying, “If you do
that, you’ll end up with this…” until they feel like they’ve found
a workable solution. Ask more leading questions for the younger ones.
The answer
here is to separate them with a filter so you get the activity of
filtration and end up with the salt water in a container and the leftover
sand/iron mixture in another. This is the perfect time to talk about how
the salt water is a solution and the sand/iron is a mixture. More info: http://www.edhelper.com/ReadingComprehension_27_39.html
Also, there
is a great flow chart here:
http://www.chemistry.mtu.edu/pages/courses/ch1120-pcharles/Oxtoby_Ch01.pdf
where your child can
learn to go through and identify whether or not these are mixtures,
compounds or solutions. Flow charts are very important in science.
Next, separate the sand iron mixture with a magnet.
Another problem will arise here. The sand sticks to the iron while it’s
wet. So you can let them try, or ask what they think they need to do (let
it dry). It will separate easily when dry. They learn about how sticky
water is, surface tension is a good discussion here. Magnetism and iron
and total cereal is a good lesson as a follow up here too.
Now you need
to separate the chemical solution, salt water. This will be difficult for
them and you may have to tell them the answer here. But first explain that
when you heat a chemical solution, you usually cause a chemical reaction
and many times, a vapor gas is given off. In this case, the salt will fall
out of solution as the vapor (water) rises as it is heated. In English,
boil it, the water evaporates leaving the salt behind.
Make sure your child writes up a lab sheet on this.
Also make sure they take notes about what they think will work and then
the results they got. You can create a lab sheet for them by going step by
step through this process and writing down good questions to ask along the
way, print the flow chart, etc and use it too. I think you’ll find many
possibilities here. I’d love to make one for you but the hand is still
on the mend and typing this today will be all I can do. I will archive
this on my site as well.
Plant ID Book and
our photos
In this activity, you will make your
own herb/weed/wildflower identification
booklet complete with pictures.
For this you will need either a
digital camera or regular camera. Go on a nature walk. This is the time of
year when weeds and wild flowers are starting to grow. On your walk, find
and take pictures of all the little flowers and “things” you see
growing. Once you have your photos in hand, get on the internet and see if
you can identify what you have growing in your neck of the woods.
Some
ways of identifying your plant use leaves. Leaf types are described by the
way they are grouped on the stalk or as stems that come off the stalk, how
many leaves are in a group and how they are
arranged. Leaves are also described by the shape of the leaf and
whether the edge of the leaf is jagged or smooth. Leaves are also
described by whether or not they have veins that run in straight lines
through the leaf or are web-like through the leaf coming off a main vein.
Other skills you will learn are how
flowers are identified, how stems are identified and how the whole plant
is identified.
To make your book you will need to
make 3 identification pages. One will describe the different leaf types,
one the different flower arrangement types and one describing stem types.
Then the following pages will be the plants and wildflowers you
photographed. On each page place a photo of the plant, it’s scientific
name and common name and then the descriptions of its leaf, flower and
stem characteristics. Be sure to use correct labeling technique when
showing the stem, leaf and flower characteristics. If you find more plants
coming up a month from now, take their picture and add them to the book.
When the season is over you’ll have the book as a memory of sunny days.
Next year when the growing season begins again, you’ll have the
identification key to use as your guide when you go on your walk. If you
photograph your child/ren with the plants, you’ll also have a record of
their growth too!
Your kids will learn to identify
common native wild plants and flowers, will learn how to make and use an
identification key and will learn the actual physical characteristics used
in identifying a plant. They will also have fun outdoors, learn correct
labeling technique and have a record they will come back to again and
again for learning and for reminiscing.
Here's some photos from our recent
nature walk:
Looking at flowers in a bug box. A rabbit hole! Resting at Nana's Lake
Quadrat Study
Quadrat studies are used by Ecologists
everyday. Children also love this type of science because it’s so fun!
Quadrat studies are done outdoors in a small square area chosen at random
and marked. You can use a wire coat hanger bent into a square, a meter
square made with pvc piping (very easy) or use pipe cleaner wire to make a
square. Officially, meter squares are used but use whatever size is best
for you. Let your child toss it into the back yard. In this square you
will get on your knees and find every living thing in the square, grass,
leaves, ants, bugs, worm, and any non-living; rocks, sand, dirt, etc. The
discovering is fun but to make it scientific and to work on those
processing skills, make a lab report.
Don’t forget to include a
hypothesis:
What do you think you will find in our
quadrat?
List materials
List procedure
Make a table with 2 columns, in one
they write the thing they find, in the second, they make hash marks every
time they find one, tallying. You can also pre-write some items to help
get them excited about things to look for.
Be sure to bring bug boxes so you can
magnify what you find.
Have your child draw some of the
things you find.
Graphing skills- Use your data to make
a bar graph of what you find.
On another day throw the quadrat in a
different area of the yard. Repeat and this time compare the 2 studies.
When we did this in college, we each did 4 then compared them with the
other 4 by other students. We then compared our own with what they got and
then put the class info together to get a total tally.
To compare ask your child to predict
if they think you’ll get a similar set of living things or many others
you didn’t get before.
Have the older child make a comparison
bar graph to compare the two graphically.
Make sure you have your child do a
write-up about the quadrat studies, comparing both populations and drawing
conclusions about why they think the amount of items found were or were
not similar.
Testing Suncscreens
Materials
Sun print paper, 3 sunscreens, transparent plastic or glass, dark cover sheet
Testing actual products is a fun way to learn science with a practical application. Ever put on sunscreen then wondered why you burned anyway? They loose their effectiveness after about 1 year. So if you intend to use your leftovers from last year, you’re taking a chance on not getting the protection you need. For this experiment, you can do two different tests. You can test 2 of the same brand of sunscreen, one purchased over a year ago and a new one or you can use it to test 3 good, not out of date sunscreens. I suggest you borrow from other families and choose some that was purchased during the summer or near the end of it, since this stuff is expensive and looses it’s effectiveness. You will need to purchase sunprint paper. This paper fades quickly in sunlight leaving designs where you cover it. Be sure not to remove the paper from it’s dark covering when it arrives. I’ve found a set on the internet (google=sun print paper) that gives you plenty for cheap, large sheets and lots left over to play with:
$11
http://www.sactoys.com/detail.asp?PID=2836&CurrentPage=
Then when you’re finished with the follow up on this, here’s some craft ideas for art work you can make with the left over sunprint paper:
http://www.diynet.com/diy/ph_photo_crafts/article/0,2025,DIY_14182_2276038,00.html
You’ll also need a clear plastic sheet like a transparency film sheet. I have some from teaching but you can also use clear plastic sheet covers, the pockets that go in notebooks, just make sure they are perfectly clear, not opaque. OR you can use glass, like something from a cheapo picture frame from the thrift store for 50 cents. You will also need a piece of paper that is dark and is the same size as your print paper. Most packages come with one. Lastly you need sunscreens. Make sure you test a store or no-name brand.
Procedure:
1.First have your child guess which one will work best.
Set up
2.Cut your plastic sheet to the same size as your paper or in a dark room, cut your photo paper to
fit your glass. Determine the size then have one of your children measure and cut to match that
size. If your package didn’t come with a cover sheet, make one to fit using cardboard or black
construction paper. You want all 3 to be the same size if possible.
3.Use a permanent (sunscreens will smear it if not) marker to divide the plastic or glass into four equal parts and label (in corner, very small) each with a letter, A,B,C,D. Then label your sunscreens each with a letter, B,C,D. “A” will be your control and will be fully exposed to the sun.
4.Place a very thin film of suncreen onto the plastic or glass from bottle B into square B. Be sure it
covers it but is still transparent. Repeat for the others.
5.Cover it with your cover sheet.
6.Pull out a sheet of sunprint paper (indoors). Make sure you know which side is active and place that face up, under the plastic or glass so that your sunscreens are sitting on top of it then your cover sheet on top of that.
7. Time to test. Read the directions and see how long your paper needs to bake. Usually it’s between 10 and 20 minutes. Take your set up outside, remove the cover sheet and set a timer or watch. Wait.
8. After the allotted time, cover your project with the cover sheet and head indoors. You’ll need to wait about 10 minutes before you can check your results.
9.CAUTION: If you remove your plastic or glass cover and toss it aside, you’ll not know where on the print paper, each sunscreen is. So before you toss your plastic or glass aside, use a pen to mark on the sun paper, your A,B,C and D.
Follow-up questions (depending on their ages)
1. Why did we place a cover sheet on our experiment? (process,logic)
2. Why did we use all four at once and not test them one at a time? (process, logic)
3. What would we look for to see if a sunscreen worked, lighter area or darker area? (process,logic)
4. Why did we have to use no sunscreen on block A? (experiment design)
5. Which sunscreen worked best? (analyzing data)
6. Did the experiment go as planned? (forming conclusions)
7. If you were to do this again, how would you do it differently? (forming conclusions)
Elements Basket
Basket 1
Everything in the universe
is made up of items from the Periodic Table of Elements. To help our
children learn to be comfortable with it and with Chemistry we can get them
a table and begin to show them what their world is made of. Get a basket or
bin and start collecting items from the table to place in the basket. Some
ideas are; a penny for copper a nickel for nickel, anything made of
aluminum, a balloon that held helium but has deflated some (so it will fit),
charcoal (or a diamond ring!) for carbon, a calcium pill or tablet for
calcium, maybe an old cobalt blue glass for cobalt, iron shavings or a small
iron skillet for iron, cubic zircon ring for zirconium. Bottled iodine for
iodine, if you can find an old thermometer with mercury add that for mercury
an old lead pipe or fitting for lead.
Basket 2
Not all elements on the
table are safe alone but when mixed with something else on the table, it
becomes a very useful item. Or it may change form into something more easily
kept. Make a second basket of items made of 2 elements from the table. Some
examples are; table salt (sodium and chlorine), flouride rinse (sodium and
flourine), gold ring (gold and silver or gold and copper), silver jewelry
(usually silver and nickel), water (hydrogen and oxygen), salt substitute
(potassium and chlorine), zinc nose coat called zinc oxide (zinc and
oxygen), exhale into glass jar (carbon and oxygen).
Games-
Blow up the table
larger with a photocopier and have your toddler put the items from basket
one on the table where they belong.
Make index flash cards of
the symbols of elements in your basket. Have your 5-7 year old match symbols
of the elements with the items from the basket. Once they've mastered that,
make cards for basket 2 with the chemical symbols for the molecules on the
cards and have them match those with the items in basket 2.
Eating the table:
Cut the ingredients and
nutrition label from a cereal box and add it to the basket. Have your child
see how many elements from the table are in their cereal they eat every
morning.
Table competition
Make a list of 20 items
from the periodic table. Give your children an allotted amount of time to
find out how these things are used. Examples; Lithium, mental health meds,
Neon, fills lights , magnesium, sparks and color for fireworks. Maybe offer
a monetary reward or ice cream! Example, younger kids, a week, older kids
maybe a few days. You could have them compete with each other but if your
house is like mine, you don't want to stir up any reason for disagreements
and battles!
Cut it out!
Make a copy of the periodic
table to cut up. Cut the squares out and have your child try to place them
together on a blank piece of paper to reconstruct the periodic table.
The goal is to have your
children become familiar with table and to lose their fear of it. Once they
feel comfortable with it, they will begin asking questions that will lead to
teaching chemistry on their level. And chemistry is the mother science. All
the other sciences begin and end with Chemistry!
What
Does It Mean To Be A Living Thing?
When
my daughter was 4 she asked me a really good question.
She said, “Momma, are cars alive?
I told her they weren’t.
I then asked her if trees were alive and she said they weren’t either.
I asked her why and she said “Because they don’t move, they just sit
there. But cars move and they make a sound.”
Would you have been able to explain to this 4 year old why cars aren’t
alive but trees are?
Science has come up with a list of things
that help decide what’s alive and what’s not.
They are:
1.Ability
to move
2.Organization
of cells
3.Homeostasis
(maintains temperature and metabolic balance)
4.Uses
energy
5.Reproduces
6.Grows
and develops
So
put some items to the test. Ask your very young children about what they think
is alive. Ask the older ones how they would tell a younger child why a car is
not alive but a tree is. Once you explain the rules for living things, put items
to the test. Go on a nature walk and choose items to run through the list. Or
stay in and use things in your home. Even if your kids are old enough to know
that something is not alive, do they know how they know?
Write a lab report
Do you do experiments with your kids? If so, if
you're not teaching the scientific method or how to write up reports, you're
missing valuable teaching opportunities. The ability to write up what you've
done in the proper way is something most college students do not know when they
arrive and consequently get their reports back with failing grades.
Begin simple by creating a form for them to fill in for now. As they get older
you can leave out the hints and helps and encourage them to write their own
reports. You can print out my sample lab here and
alter it to your needs by making or leaving out blanks or leading information
but the components of the report must stay.
Design your report as follows:
Title
Purpose
Hypothesis about what will happen
Procedure for the experiment
Data or results (unbiased)-use tables, pictures and/or drawings. Always graph
your results!!
Conclusion (opinion)
Nature Walk
If you're tired of being inside, go on a nature
walk. You'll need to purchase a magnifying box. They are only $2 from most
science supply companies. This is one from a jewelry company (1.50). I think
they're also called bug boxes.
http://www.openallday.au.com/Magnifying%20Boxes.html
Here's a science site that also has some good games resources, assessment
methods and science in art. (bug box is 1.59)
http://www.acornnaturalists.com/store/product1.asp?Product_ID=1558
On your walk, find things to put in the box. It doesn't have to be bugs.
Flowers, seeds, dirt, rocks, grass, anything works. Your child makes a sketch or
drawing of what they see with it magnified. When you get home. Look that item up
on the internet and see if you can find it labeled or any information about how
it is described. Have your child label the drawing using the correct scientific
terminology.
Nature Walk II
This nature walk is about Fibonacci.
He discovered a number pattern that is famous in the math world because it is
also found in nature. You've seen it everywhere. Like:
Petals on flowers, seed heads, pine cones, leaf arrangements,
leaves per turn, vegetables
and fruit, like pineapple, snail shells and most famously- the Nautilus shell.
The pattern is that when you add any two consecutive numbers
you get the next number in the sequence. Here's the number pattern: 1,1,2,3,5,8,13,21,34.......
When you add 2 and 3 you get the next number in the sequence,
5.
So, go looking for Fibonacci. Either draw or photograph what
you find and make a Fibonacci lap book or scrap book or anthology or work of
art.
Celery
I know you may not have a microscope yet, but if you do, here's an activity for
you. If you don't, it's a good idea to begin saving for one. It's a necessary
tool for science teaching.
Take a stalk of celery with leaves still on it and place it in a glass of
colored water, leaves up. Red works best. After about 24 hrs, the leaves will be
red.
Hypothesis, why/how did the leaves turn red.
Cut the stalk in half. Have your child draw what the cross section looks like.
Now use a razor blade to slice a very thin piece of celery, so thin you can see
through it. Place it on a slide and view the red stained "channels" on
the lowest magnification.
Have your child draw what they see. Look up zyloem and phloem on the internet
and have your child decide which channel is zyloem and which is phloem.
This sounds boring but have you ever seen these channels magnified? It's
absolutely amazing!!! Especially when viewed on the highest magnification. It's
beautiful and
amazing! It looks like this drawing
which is also Fabanacci!
So have your child label the zyloem and phloem and then discuss with you how they now think the water got to the leaves.
Have them count how many channels there are.
There's no need to fear that your 4 year old can't do this. 4 and up should have no problem with it.
Measuring A Million
It's hard to imagine how much is a million so sometimes it helps
to do an activity such as this.
You'll need 50 sheets of paper and a calculator. Be sure to do
all measurements in metric.
First guess.
How tall would a stack of 1 million sheets of paper be?
Stack 25 sheets of paper then measure the height of it.
Stack 50 sheets and measure it.
Based on these measurements, how tall will a stack of 100 sheets
be?
If 100 sheets is _______ cm tall then how tall are 1,000,000
sheets?
To get your answer:
How many 100 sheets of paper are in a million? Divide 1 million
by 100.
Multiply that answer by the height of 100 sheets.
Now you have a large number in cm. There are 100 cm in a meter
so take 2 zeros off your answer and you have meters. (see why metrics is easy?)
A
meter is closely equivalent to a yard. For perspective, a football field is 100
yards long.
You can take this further by going outside and walking the meter
distance while remembering you are walking the "stack" of 1 million
sheets of paper.
World Population Activity
The world population reached it's 6th billion in 1999. It took
the human race all of time up until the year 1800 to populate the Earth with 1
billion people. But it only took 150 years to get our second billion in the year
1930. How quickly did we get the rest of them? Each billion came faster and
faster. Here's an activity to help your child see a graphic representation of
our population growth. You will make 2 time lines. You will need long thin paper
like connected computer paper cut in half lengthwise or cut several sheets of
paper in half lengthwise and tape them together end to end to make a
strip. You will be plotting from the year 1AD until the year 2000.
To mark these, fold the paper in half to find the halfway point and mark that as
the year 1000AD. Continue folding to find the halfway points between the plotted
years.
Before giving your child the data ask them to predict how many
people they think are on the earth.
Once you mark the years from zero to 2000AD you should end
up with the 1900's being about the width of your finger at the end of the paper.
I500
I1000
I 1900
Color the first 1 billion people all one
color up to the year 1800.
1800
Color from 1800 to 1930, another color.
Continue in this fashion until the end. Fill in the following
data.
|
Year |
Billion |
|
1800 |
1 |
|
1930 |
2 |
|
1960 |
3 |
|
1975 |
4 |
|
1987 |
5 |
|
1999 |
6 |
After making this timeline, create another one that only
covers the 1900's. Fold in half and mark the center as 1950 and complete in the
same fashion. Mark each billion and notice the result that cannot be seen on the
first timeline.
Use these questions as follow up questions:
1.Were there any people on the planet before the year 1 AD?
2.What conclusion can you draw about the intervals between each
billion?
3. What happened to the interval between the 5th and 6th
billion?
4. Name some things that could have contributed to this change.
5. If this pattern continues, when will we get our 7th billion?
6.Graph the number of years between each billion. Put years on
the vertical axis and put the intervals on the horizontal axis. Plot 2-3,
3-4, 4-5, and 5-6.
