Title of Lesson Understanding Sand

Subject Area A lab designed to teach students what sand is from a physical classification standpoint and how sand can differ from beach to beach.

Age or Grade Level 7th grade

Brief Overview

This lab is designed as an introduction to the idea that sand is actually a geology size classification, and the term “sand” itself only denotes particles between 1/16mm and 2mm in size.

Ideally within this lab, the class will have collected sand from various beaches (the more the better) and the observation (via microscope) along with some rudimentary chemical reactions (Calcium Carbinate with vinegar) to help distinguish between various sand protoliths.

This topic is especially relevant for schools near water (such as Quincy) and can be easily transitioned into a lab or discussion about beach erosion from a physical and chemical perspective. I believe this lab is a great way to start an overall environmental science unit.

Basic classification of sand requires a microscope and different types of sand. Students will sort out types of sand via 2 qualitative characteristic (angularity and morphology), 2 quantitative characteristics (sorting percentage and specific grain sizes) and one chemical reaction (acid-base reaction).

The chemical reaction component can be be as expansive as using HCl (not recommended for a middle school setting) or easy as using vinegar. Ideally, one of the sand samples should be calcium carbonate sands, but that might be hard to obtain in certain locations. As a substitution, we can use TUMS (or another easily obtainable calcium carbonate based medicine) which has been crushed into small pieces. The vinegar (an acid) should react with the CaCO3/TUMS (a base) and fizz with many bubbles. This is indicative of a release of CO2 gas.

See Attached documents for a methodology of lab experiment, examples of different types of sand worldwide, and analysis questions.

Estimated Time This lab will work best as two classroom days. The first day will consist only of analysis of sand samples. Day two can be dedicated to analysis of the different types of sands and the

various observations made from different sand types.

Standards/Unit Goals Students will be able to determine differences between types of sand and understand how the properties of sand can be connected to beach erosion and weathering.

Essential Questions

1) What is sand (from a physical perspective)

2) Where does sand come from, and how can this vary? (Introduce vocabulary word: ‘Protolith’)

3) What can sand tell us about it’s protolith and local environment/geology?

4) What are the different ways to differentiate between sand?

5) Why do you think some sands reacted with the vinegar and some did not?

6) Why is sand type important to beach erosion?

7) How can different types of sand erode as different rates?

Skill Objective(s) By end of this lesson, students will be able to

Understand the concept of sand and it’s effect of beach erosion and protolith environment.

Knowledge Objective(s) By end of this lesson, students will know

- Understand the variations in sand types

- Microscope skills and measurements made under a microscope.

Materials Needed

- Microscope (40x ideal, but whatever is available will work)

- Various types of sand. At the very least twodistinct locations but the more the merrier.

- Calcium Carbonate sand. If none is available, substitute crushed up TUMS.

- Rulers (with mm measurements)

- Vinegar

Technology Tools Used Microscope. Acid (vinegar is ideal) Useful Vocabulary .Protolith, Grain Size, Angularity, Grain Size Sorting New Vocabulary Word 1

Prerequisite knowledge/skills Knowledge of the rock cycle. How weathering and erosion occurs (but not to a great extent)

Anticipated Student Preconceptions/Misconceptions

Students have probably only been exposed to sand as part of a beach. This lab is designed to introduce the idea of sand as a size classification. As such, different sized clasts might be useful to show the difference in grain sizes.

In order to determine the “sorting” of the sands, students will have to isolate ~100 grains. This might be hard and/or tedious for certain kids. Be sure to keep them on task!

Instructional Tips/Strategies for the Teacher

Lesson Sequence

Opener. Introduce the lab and have students review the lab procedures. Introduce the concept of sand as a size classification. Have students list and talk about where they have seen sand or been exposed to it (before and after defining the size classification)

Lab. Students should split up into groups of 2-6 (depending on availability of microscopes and number of sand samples).

Have each group determine the average size of the sand grains (using a mm ruler) and average angularity of the sand particles.

Each lab group should separate ~100 grains of sand and then calculate the “sorting” of the sand. (i.e. well sorted to poorly sorted). In each group there should be a designated recorder along with 2 or 3 “counters”. Roles should remain the same through the course of the lab.

Once the above activities are done, it is time to test the chemical reactions within the samples. Take the vinegar and drop onto the various sand samples. When the vinegar touches the calium carbonate sand (or TUMS) it should start to fizz. Have the students brain storm why that may be happening.

Closure: Lead a discussion on the various types of sand the students have observed. As a class talk about the variations in grain size and sorting, along with angularity of different samples.

This portion should lead to an overall discussion on beach erosion and weathering. Ask students how different types of sands might be eroded differently than other types of sand they have observed. Introduce the idea of ocean acidification. Could a higher pH (like vinegar) affect beachs made out of CaCO3?

Resources Weblinks Reproducible Materials

See attached pdfs below

References

Assessment Students should conduct a small report (or homework assignment) on the different sands seen around the globe and from personal experience.

Extensions/Explorations

Reflections Contact Information

Understanding  Sand  -­  Lab  Activity  

Materials  &  Procedures  

 

Materials  and  Equipment  Required:  

- Microscope  (40x  ideal,  but  whatever  is  available  will  work)  

- Various  types  of  sand.  At  the  very  least  two  distinct  locations  but  the  more  the  merrier.    

- Calcium  Carbonate  sand.  If  none  is  available,  substitute  crushed  up  TUMS  or  antacid.    

- Rulers  (with  mm  measurements)    

- Vinegar  (or  some  other  type  of  acid)  

 

Procedures.  

1. Carefully  set-­‐up  microscopes  and  associated  slides  or  dishes  to  be  analyzed  2. Prepare  samples  of  sand  for  microscope  

a. This  can  include  putting  a  small  amount  of  sand  on  a  slide  or  on  a  larger  glass  dish  (whichever  fits  on  the  microscope  stand)  

3. Designate  roles  within  the  lab  group  a. 1  Recorder  b. 2-­‐4  Observers  c. 1  Measurer  (in  charge  of  size  measurements  and  grain  size  

calculations)  4. Carefully  place  sand  samples  underneath  the  microscope.  

a. Make  initial  observations  of  sand  underneath  the  microscope.    b. Describe  in  lab  notebook  some  qualitative  (non-­‐technical)  

characteristics  c. Observations  can  include:  

i. Colors,  Shapes,  Sizes,  Opacity,  etc  5. As  a  group  determine  the  overall  angularity  and  sphericity  of  the  sand  grains    

a. Use  given  chart  to  make  this  determination.  Remember,  this  is  an  average  angularity  and  sphericity  of  the  entire  sample.  Use  the  terminology  shown  in  the  chart  

b. You  will  see  different  angularities  and  sphericities  within  the  sample.  As  a  group  you  must  come  to  a  consensus.  This  will  require  team-­work  and  repeated  observations.  

c. Write  down  the  justification  for  your  lab  group’s  choice  in  your  lab  notebook.  

6. As  a  group  determine  the  range  of  sand  grain  sizes  in  your  sample.    a. Have  one  person  be  the  designated  measurer,  but  have  the  rest  of  the  

group  check  the  work  and  make  his  or  her  own  observations.  7. Select  ~50  grains  from  your  sand  sample  

a. Determine  an  average  grain  size  for  your  sample  b. Determine  the  sorting  of  the  sand  sample.  

i. Refer  to  chart  below.    ii. Show  the  percentage  of  large/medium/small  grains  before  

defining  the  final  grain  sorting  classification.  iii. Remember,  sorting  refers  to  the  variation  in  grain  sizes  within  

your  sample.  c. In  your  lab  notebooks  write  a  sentence  on  how  human  bias  could  

affect  grain-­‐sorting  classifications.  8. Collect  a  Calcium  Carbonate  Sand  sample  (might  be  crushed  up  antacids)  

from  the  teacher  a. Quickly  calculate  the  grain  sizes,  angularity/sphericity,  and  overall  

grain-­‐sorting  of  this  new  sample.  9. Drop  a  teaspoon  of  vinegar  on  your  orignal  sand  sample  and  on  your  new  

carbonate  sand  sample  a. In  your  lab  notebook  describe  what  happens  in  each  instance  b.  What  do  you  think  is  happening  with  the  carbonate  sand?  c. Why  do  you  think  something  different  happening  in  your  original  

sand  sample  10. Clean  up  sand  from  your  work  area.  Prepare  and  clean  microscopes  for  the  

next  class.  

 

 

 

 

 

 

 

 

 

 

 

Some Common (and Uncommon) Examples of Sand