back to basics

Many students find Science difficult, it really doesn't have to be.

Science and particularly Chemistry, requires students to visualise particles, atoms, molecules etc on a microscopic scale.  So, most teachers frequently use models on a macroscopic scale to help students with this crucial part of the learning process.  Here's my back to basics on the particles that make up water.

Place 3 beakers containing ice, water and steam on a desk at the front of the room.  Get your students to draw a quick sketch of what they see.


If you work in a laptop school, students may like to use diagram maker or lab equipment for their sketches, but hey, there's nothing wrong with a simple pen and pencil.

Next step, ask your students to draw particles in the beaker that make up the 3 different states of water.  Students usually represent particles as circles (although they could be shown as triangles, squares, hexagonals, any shape really!).  Here's 3 simple animations showing the particles in water in 3 different states.

animations are from the Royal Society of Chemistry

There are many experiments that can be carried out that involve a change of state, students can make models, do a class roleplays etc...  The bottom line is that science students need to have a clear idea of the movement and energy of the particles and their resultant effect on the volume, shape and relative density of solids, liquids and gases.
Following on from the movement of particles, students may carry out a heating curve experiment, plot a graph and analyse each step in detail, see below a graph showing the changes of a state.

animation from Footprints

Finally, onto step 3...recap on the chemistry term for water being H2O, which can be shown visually as

and moving away from the phrase "particles" but making use of the words atoms and molecule to describe water, get your students to sketch the beakers of ice, water and steam in terms of atoms and molecules.  Vision Learning has 3 superb and clear animations detailing the molecules of water in the 3 different states, see the screen shots below.

 images from Vision Learning

For senior students, hydrogen bonds between the water molecules are shown. 

As a teacher, you may be surprised the learn that the majority of students assume that in the gas state, the water molecules separate to form oxygen and hydrogen atoms, this isn't the case.  A simple demo of the hydrogen balloon (or hydrogen and oxygen balloon) and prior knowledge that a match near water vapour from a kettle does not result in an explosion, will help students to realise this.

Also, worth a mention is this interactive animation "Particle viewer of objects in a room", whereby students can click on different objects and get a peak at how the atoms are arranged.  This again, helps students to visualise the atoms in the objects on a microscopic level.

And molecule 3d, mentioned on my previous blog "water hydrant" in which students can make up their own simple molecules, then view them in 3d.  It's quick and straightforward, although for senior students I'd recommend Chemsketch and Chime.

This document titled "On the Ball" from The University of Southhampton, 2001 emphasises the importance of using models in the teaching of Science and has many suggestions and ideas on the uses of models in junior science.

This report "Beyond appearances, students misconceptions about basic chemical ideas", Vanessa Barker highlights in detail many misconceptions that students have and suggestions on what we can do as teachers to help students develop the "molecular spectacles" required to progress further with their chemistry knowledge.

Finally, here is a wonderful animation on dissolving salt in water which shows clearly that even though the salt cannot be seen it has not "disappeared" and that the mass of the beaker containing dissolved salt and water is not the same as the beaker of water.  Yep, another couple of common misconceptions there.


Senior students will find this animation useful to help them to visualise and explain in detail the solubility of an ionic substance such as NaCl in a polar solvent such as water and here is a worksheet from the RSC on mass and dissolving.

I hope those of you in the Northern Hemisphere are enjoying a steaming and stinking hot summer, I'm off to splash about in puddles as its raining cats and dogs down here.

ps: to download any animations shown above...

1) use Mozilla Firefox to open this internet page

2) top of page click Tools, then select Addons and Get Addons

3) type in "Embedded Objects"

4) restart Firefox

5) click the little green arrow (bottom right) and the animations/videos from any site you visit will be saved to your computer

end of term videos

I'm weary...worn out....11 week term was too long...light at end of tunnel...end of term tomorrow...YAY!

I'm officially too tired to teach tomorrow so it'll be a video day of "popcorn lessons" for me and my students.

Here's my top ten (well actually, nine) list of end of term videos...in no particular order...

March of the Penguins

Documentary film narrated by Morgan Freeman: A wonderful, emotional and very visual journey that relates to adaptation and habitats.

"The film depicts the yearly journey of the emperor penguins of Antarctica. In autumn, all the penguins of breeding age leave the ocean, their normal habitat, to walk inland to their ancestral breeding grounds. There, the penguins participate in a courtship that, if successful, results in the hatching of a chick. For the chick to survive, both parents must make multiple arduous journeys between the ocean and the breeding grounds over the ensuing months."

BBC Blue Planet

Time flies as you sit back and effortlessly watch any of the 8 of these 50 minute episodes with links to adaptation.  I recommend episode 2 "The Deep".

"The Blue Planet has been described as the first ever comprehensive series on the natural history of the world's oceanseach of the eight 50-minute episodes examines a different aspect of marine life.  My favourite is episode 2 "The Deep", it's just extraordinary. The underwater photography includes creatures and behaviour that had previously never been filmed."

Man on Wire

WOW! I'm a little speechless, what an incredible lifetime dream that was achieved by Philippe Petit! Show this in class after teaching a unit on forces, it is a gripping documentary and a well deserved winner of numerous Film Awards.

"On August 7th 1974, a young Frenchman named Philippe Petit stepped out on a wire illegally rigged between New York's twin towers, then the worlds tallest buildings. At 7:15 AM, Philippe took his first step on the high wire 1,350 feet above the sidewalks of Manhattan. James Marsh's documentary brings Petit's extraordinary adventure to life through the testimony of Philippe himself, and some of the co-conspirators who helped him create the unique and magnificent spectacle that became known as the artistic crime of the century"

Atom Bond, the atom with the golden electron

I cannot recommend this highly enough, it is superb, a fun, creative and informative summary for Senior Chem students on bonding and intermolecular forces.  Available to purchase from Classroom video.

"The scientific concepts are presented as a parody of a James Bond movie: Gold Metallic Bond is sent off to investigate why carbon, nitrogen and other atoms are training themselves in other types of bonds. He discovers their 'bond' school and university, finding that they are all working towards Project D. Complex information is presented in a way that is designed to be fun at the same time."
Winner of a Gold Dragon at the International Science Film Festival 2001 Beijing and gold medal for the Most Innovative program at the Questacon (CSIRO) Awards 2001.

BBC Life of Plants

A wonderful series, written and presented by David Attenborough. Due to time constraints it's unlikely you'll be able to show all six episodes, I recommend episode 1 "Travelling", which introduces students to many weird and wonderful types of seeds and their methods of dispersal.

Man v's Wild

Hosted by Bear Gryllis (surely, not his real name!).  Have a look at the Namibian desert episode (season 2, episode 9) where he puts together a makeshift water distiller and finds sources of water in the desert, there are loose links to distillation and adaptation.

I came, I saw, I redoxed

Another favourite from the Classroom video crew this is an excellent summary of redox chemistry for your senior Chemistry students.

"This video explains or redox reactions via an animated story in which the mighty caesium and his legion of atoms set out to conquer the world. A number of reactions are covered and the properties of different types of atom explained."

Wallace and Gromit by Nick Park of Aardman Productions. 

These plastercine charachters are very popular with students, all three of the 20 minute episodes are worth a look. I recommend "The Wrong Trousers" with links to levers and forces, this episode alone has won over forty top international awards including the Academy Oscar, and has become one of the most successful animated short films ever made.

As a side note, there is a "Wallace and Gromit, World of cracking ideas" exhibition on at the Science Museum in London until November 

Atoms and their electrons

The synopsis below sounds cheesy, because it is! This is a fabulous summary of ionic, covalent molecular, metallic and covalent network bonding.  Another highly recommended video, available to purchase from...yes, you guessed it, a very creative and talented group of professionals at Classroom video.

"This program provides a history of our understanding of the atom including the pioneering work of Dalton, Thomson, Rutherford and Bohr. It features an animated love story of chlorine and sodium, showing how 'at the disco' atoms combine in various ways. Carbon forms a show of network covalent models, we see evolving molecular shapes C02, H20, NH3, CH4, and N2. Chlorine is asked to dance with Ca, Al and C but waits for Na. They dance and transfer an electron. Love at last."

Happy holidays!  Enjoy a relaxing and restful break :-)

Periodic table problems

Six months have passed since I started this blog and can you believe it, not once have I mentioned the Chemist's "bible", the Periodic Table...  There are many, many versions of the Periodic Table online, I recommend these two...

WebElements Periodic table

Visual Elements Periodic table

For Senior students, the David Whizzy Periodic table is excellent

 David Whizzy's table (screenshot shown above) has good, clear visuals of the electrons in the s, p, d orbitals along with the charachteristic emission spectrum for each element.

Extension students of all ages may be interested in taking a look at the progression of the Periodic table over the centuries and can view the many different forms of the Periodic table here on the informative Periodic Table Formulations site

A fun way to introduce the Periodic table is with the Tom Lehrer "Elements song" from 1952, as mentioned on my previous blogpost titled "Eurovision song contest"

There is a small selection of periodic tables below which enable students to experience some of the frustrations of the early chemists as they tried to arrange the elements, I'd recommend that students work collaboratively is small groups as they discuss one of all of these.

	Periodic table discovery activity
	Periodic table of extraterrestrial elements
	Merrymen of Matterdom image and teacher guidelines here

I like this 4 minute video from Teachers Domain called "The elements forged in stars", it "illustrates the critical role that the stars play in creating the elements".

and for revising previous knowledge of the Periodic table try this Alien Periodic table with teacher answers here.

and for more Senior students a good challenging problem is the Periodic difficulties with teacher answers here.

and a concept map of the Periodic table from the Royal Society of Chemistry.

A finally a Periodic table of Comic books, who would have thought!  The links to elements are a little loose but may certainly inspire your students to think up and then sketch their own cartoon strips that illustrate the properties of, sources of or uses of elements in the Periodic table.

Go the All Whites!!! Who would have thought, good on you New Zealand, that small island on the edge of the Pacific, that was a wonderful goal and unexpected draw against the World Champions.  Best of luck against Paraguay in a few hours time.

Football

"Football is not about life or death. It is more important than that."

Bill Shankley, former manager of Liverpool Football club.

Well it's rolled around again... FOOTBALL (most certainly not soccer!) fever.  I wonder what surprises the FIFA World Cup 2010 has got in store for us?  There have been the usual dramas and injuries leading into these finals, Thierre Henry's "Hand of Frog" didn't go unnoticed by anyone, oh except of course the ref!

Injury has dashed numerous players (and their fans) World Cup dreams, the English and German teams will be the most affected without Beckham, Ferdinand, Ballack, Adler, Traesch and Westermann.  Before it all kicks off, take a trip down memory lane and have a look, a cheer at these top 50 World Cup moments from The Daily Telegraph.

So how can we encorporate the Football World Cup into our science lessons?  Here's a few suggestions...

1) Analysing distance-time graphs, produced by ASE in 2001
Students will look at actual video footage from an FA Cup 4th round match between Manchester United and West Ham United.  It is a little dated as it was played back in 2000, however, there are 6 different stages and students should make a note of the key point for each stage.  The accompanying key point worksheet is here.

2) video "The Science of Football" 
Encourage your students to improve their science knowledge and football skills (with a lot of practice!) after viewing this engaging video on the science of football.

3)  Article "The physics of football" by Physics World 
Senior Physics students may like to read this article which discusses the spin, velocity and forces as a football is kicked with a curve.

Finally, you must have seen the Nike Football "Write the future" adverts.  I like this overwhelmingly positive review on the Nike Football ads from the soccerbible.com

"Starring some of the world’s best players, including Cristiano Ronaldo, Didier Drogba, Wayne Rooney, Fabio Cannavaro, Franck Ribery, Andres Iniesta, Cesc Fabregas, Theo Walcott, Patrice Evra, Gerard Pique, Ronaldinho, Landon Donovan, Tim Howard and Thiago Silva... this epic football journey unfolds through a match of goal line clearances, game-winning tackles and lightning footwork that literally send a ripple effect across the world."

Have a fantastic month cheering on your team. Enjoy the excitement, tension and tears of joy. Relish in that sense of camaraderie and the community feel of it all during the most watched sporting event in the world.