The Kitchen Science of Crystals
Lesson 8
ECH 430- Assignment 3
Student Number 42065712
Lesson 8: Group Presentations
Stage 2
Outcomes and indicators
ST2-8ES describes some observable changes over time on the Earth’s surface that result from natural
processes and human activity
ACSSU075 Earth's surface changes over time as a result of natural processes and human activity.
 Students are provided with the opportunity to use appropriate tools and equipment to observe
crystals, and record data
ST2-12MW identifies that adding or removing heat causes a change of state between solids and liquids
ACSSU046 A change of state between solid and liquid can be caused by adding or removing heat.
 Students will describe some everyday situations where solids and liquids change state by adding heat
(heating) or removing heat (cooling)
KLA integration:
 TS2.2 Students will engage in active interactions with their peers discussing the topic, sharing their
knowledge, thoughts, and ideas
 UTS2.9. Students will use computer-based technology, materials and other resources to design and
create presentations
 VAS2.1 students will engage in visual activities as they create/ draw and design their presentations
Activity: Creating presentations about crystals
For this experience students will work in groups to create a PowerPoint presentation or poster
demonstrating their own understanding and findings of the sugar and salt crystal experiments
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Students will engage in a collaborative, hands-on experience as they use a range of materials, or
technology to create a poster, or a PowerPoint presentation
Key Scientific Knowledge
In order to effectively initiate this lesson, it is pertinent that the teacher has a concrete understanding of all
the content that has been covered so far in the unit. Knowledge of the various aspects of crystals, such as
what a crystal is, how they are formed, and the different types is essential.
Crystals are a result of atoms that combine together to produce a repeated pattern of molecules, and thus,
form a solid shape. Crystals can be either natural or manmade (artificial) (Campbell, 1998-2011).
There are seven different types of crystal structures - Cubic, Trigonal, Triclinic, Orthorhombic,
Hexagonal, Tetragonal, and Monoclinic (Science for Kids, 2013). The individual crystals are so tiny
they can only be seen under a microscope. Each structure represents some form of three-dimensional
shape, such as a cube, prism, or pyramid. Snowflakes are an interesting form of ice crystal as no two are
ever the same shape/structure. Crystals can also be found in kitchen ingredients such as salt, sugar and
baking soda. Crystals can also be classified according to their chemical and physical properties, falling in
to one of four categories, known as, Covalent crystals, Metallic crystals, Ionic crystals, Molecular
crystals (Campbell, 1998-2011).
The Kitchen Science of Crystals
Lesson 8
ECH 430- Assignment 3
Student Number 42065712
Resources
(For teacher) Summary notes on content (see appendix/link)
Laptops/ computers
Cardboard /Paper variety
Writing/ craft materials
Overview of Lesson
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Introduce/ begin lesson by providing students with the opportunity to share something they have
learnt about crystals - do a class brainstorm on the IWB
Divide students in to groups of four or five (according to class size)
Students will be provided with the options of either a PowerPoint presentation or poster
To ensure a range of aspects are covered, each group must decide on a different focus area (have
ideas pulled out of a box if necessary)
Potential aspects of focus content;
- What is a crystal? Give one example i.e. snowflakes
- How are crystals formed? Give an example of one
- different types of crystals, choose one to explore further in depth
- process of Salt/Sugar crystals
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Students will then work collaboratively to present what they have learnt about crystals
Students will be encouraged to be creative and innovative to make their presentation piece
interesting and engaging. Opportunities to work on the presentations will be provided during other
lessons such as Literacy and Art
Conclude lesson by engaging students in a brief activity
- The activity involves each student to write down at least one piece of information about
something they have learnt or find interesting about crystals. Papers will be collected by the
teacher
References
Board of Studies. (2007). K-6 English Syllabus. Board of Studies: NSW
Board of Studies. (2007). K-6 Creative Arts Syllabus. Retrieved 21 October, 2013, from
http://k6.boardofstudies.nsw.edu.au/files/arts/k6_creative_arts_syl.pdf
Board of Studies. (2013). K-10 Science Syllabus. Retrieved 21 October, 2013, from
http://syllabus.bos.nsw.edu.au/science/science-k10/
Board of Studies. (2006). K-6 Science and Technology. Syllabus. Retrieved from
http://k6.boardofstudies.nsw.edu.au/files/science-and-technology/k6_scitech_syl.pdf
Campbell, HA. (1998-2011). What types of Crystals are there? Kiwi Web: Australia and New Zealand. Retrieved 22 October,
2013, from http://www.chemistry.co.nz/crystal_types.htm
Science For Kids. (2013). Crystals. Ducksters. Technological Solutions. Retrieved 21 October, 2013, from
http://www.ducksters.com/science/crystals.php
The Kitchen Science of Crystals
Lesson 8
ECH 430- Assignment 3
Student Number 42065712
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Crystals come in two main forms – natural and manmade.
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Natural crystals are formed under the earth’s surface from a combination of
temperature and compression to form different shapes, whereas artificial
(manmade) crystals are created in a laboratory
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Crystals are a result of atoms that combine together to produce a repeated pattern
of molecules, and thus, form a solid shape
(Everything about crystals, 2013; Kiwi web, 1998-2011)
Cubic (Isometric) Crystals
 Not always shaped like a cube
 Isometric – three sides with the same length, height and breadth
 Can be shaped like a octahedron (8 sides) or dodecahedron (12 sides)
 Salt is an example of a cubic crystal found in natural crystals
Trigonal Crystals
 Four axes, with three that are equal in length and one that is longer/shorter
 Similar to hexagonal crystals due to its physical shape, except trigonal structure is
less defined
 Quartz is one of the most common forms of trigonal crystals
Tetragonal Crystals
 When looking through a microscope there structure is very similar in shape to cubic
crystals except they are longer in length
 look like prisms and double-pyramids
Monoclinic Crystals
 Also form as prism shapes or double pyramids
 They appear to have been titled which makes them look different to cubic and
tetragonal crystals
 Most common crystal structure
 One of the least symmetrical structures
The Kitchen Science of Crystals
Lesson 8
ECH 430- Assignment 3
Student Number 42065712
Orthorhombic crystals
 Also appear like double-pyramids (two stuck together)
 Looks like tetragonal crystals, although the centre where the pyramids join is not a
square
Hexagonal crystals
 Six-sided - Looks like the hexagon shape, only in prism form
 Sides may not always be even, but the crystal will still have six
Triclinic crystals
 Least symmetrical – no equal sides or angles
 can be very strangely shaped
(Gardiner, 2007; James, 2011; ThinkQuest, 2013; The natural sapphire company, 2013)
Covalent Crystals
 All the atoms share the electrons that form a bond to create a solid shape
 “One big molecule”
 High melting point
Metallic Crystals
 Individual metal atoms
 Outer atoms flow freely around the structure/ shape
 High melting point
Ionic Crystals
 No covalent (shared) bonds between atoms
 Atoms held together by slow-moving force
 Often have a hard structure, high melting point
Molecular Crystals
 Structure is soft, low melting point
 recognizable molecules that are held together by hydrogen bonds
 Sugar is a type of molecular crystal
(Campbell, 1998-2011)
The Kitchen Science of Crystals
Lesson 8
ECH 430- Assignment 3
Student Number 42065712
 Are an interesting form of crystal, known as Ice Crystals
 Formed when water freezes up in the clouds
 No two snowflakes are ever the same – each have their own beautiful and unique
structure
 Temperature has a big influence on the shape the snowflake will be, and since
temperature is always changing, different snowflakes are always created
 So tiny it is only possible to see their complete structure under a microscope
(Kidzworld, 2013; Maki, 1993; Science for Kids, 2013).
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Crystallization refers to the separation of solids (salt/ sugar) and liquids (water) that
occur during the experiment, and thus, work together to create a crystal.
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Through the process of crystallization, the separated crystals move closer together to
form a bond in a pattern-like manner, and thus, form a larger crystal
(Maki, 1993)
References
Campbell, HA. (1998-2011). What types of Crystals are there? Kiwi Web: Australia and New Zealand. Retrieved 22 October,
2013, from http://www.chemistry.co.nz/crystal_types.htm
Gardiner, L. (2007). Shapes of Mineral Crystals. Windows 2 Universe. Retrieved 22 October, 2013, from
http://www.windows2universe.org/earth/geology/crystal_shapes2.html
James, R. (2011). The Seven Crystal Systems. Your Gemologist. Retrieved 22 October, 2013, from
http://www.yourgemologist.com/crystalsystems.html
Kidzworld. (2013). All about Snowflakes. Retrieved 21 October, 2013, from http://www.kidzworld.com/article/1587-all-aboutsnowflakes
Maki, C. (1993). Snowflakes, Sugar, and Salt. Crystals up close. Learner Publications Company: Minneapolis.
Science For Kids. (2013). Crystals. Ducksters. Technological Solutions. Retrieved 21 October, 2013, from
http://www.ducksters.com/science/crystals.php
The Natural Saphire Company. (2013). Trigonal Crystals. Retrieved 22 October, 2013, from
http://www.thenaturalsapphirecompany.com/education/related-information/trigonal-crystals/
ThinkQuest. (2013). Crystal Systems. Cubic Crystals. Retrieved 22 October, 2013, from
http://library.thinkquest.org/C005277/Crystal.html