Today we will be doing an experiment with acids and bases – making a pH indicator using red cabbage and testing various household substances. PH is a measure of the acidity (ph is less than 7) or alkalinity (ph is greater than 7) of a substance.
The picture above shows a laboratory centrifuge, which might be used to collect DNA from tissue samples. Other uses for centrifuging are when you make billy tea – spinning the billy to make the tea leaves settle at the bottom. You might even have been in a human centrifuge at the show or Luna Park!
You can learn more about Separating Mixtures by going to our Year 7 Maths and Science wiki – you will need to register if you don’t already have a wiki account (use your school email) and join the wiki. You will find lots of activities there to keep you busy (and learning!) over the holidays!.
Try this fun quiz at Quia to test your knowledge about Separating Mixtures: http://www.quia.com/rr/450972.html
Henry asked an interesting question today – Is welding a physical change or a chemical reaction? To find out we need to think about the following questions:
- Can the change be easily reversed?
- Are there new products formed?
- Is there a change in colour?
- Are there any gases or precipitates formed?
You can read more about the science of welding here.
Some welding videos here.
(Year 7) This activity from the Learning Federation asks you to sort different objects into solids, liquids and gases.
What the world is made of (Sorting matter): http://www.eduweb.vic.gov.au/dlrcontent/4c33323530/index.html
Learn about different ways to separate mixtures using these on-line activities:
Making water drinkable: http://www.eduweb.vic.gov.au/dlrcontent/4c33313938/index.html
Making water drinkable (Mixtures): http://www.eduweb.vic.gov.au/dlrcontent/4c33313030/index.html
Making water drinkable (Water treatment): http://www.eduweb.vic.gov.au/dlrcontent/4c33313033/index.html
Matty created the great quiz below using “My Studiyo” , a free software program that allows you to customize the template, add images and score multiple choice or True/False questions.
After our experiments to evaporate the water from soft drink and create crystals from a filtered copper sulphate solution, we will have an assessment task – separating rice grains, salt, iron filings and sand from a mixture of these components.
Here are some sites to help you learn more about separating mixtures:
A worksheet to complete: http://www.hi.com.au/resource/science/pdf/Mixtures2.pdf
Separating salt and sand: http://www.zephyrus.co.uk/separatingmixtures1.html
Separating iron from sand; http://www.mikecurtis.org.uk/mixtures.htm
CATALYST (video): Recycling water
CATALYST (video): Froth Flotation
Photos sourced from Flickr (CC) and saved in Irfanview.
After five weeks of term studying atoms and elements, molecules and compounds, the periodic table and the carbon cycle, we are ready for our first test. Make sure you revise all of Chapter 2 thoroughly and complete the “Summing Up” section at the end of the chapter. You will be required to memorise the first twenty elements of the periodic table (names and symbols), which will be worth 20 points. This will be of great assistance for science in future years. You can use the mnemonic “Little Betty Boron Chews Nitrogen On Friday Nights” and “NaMgAl SiPS Chlorine Ardently” to help you remember most of the first twenty.
You will also need to know the three different forms of Carbon – as shown above, Diamond, Graphite and Charcoal.
Beth Still from the Nebraska Educators Network follows Will Richardson on Twitter, which had a link to this great site for chemistry teachers: The Periodic Table of Videos – short videos about each of the elements of the periodic table. So I’ve been back to Twitter and found some friends, and now I think I understand better how it works. It seems nothing I try really takes off the first time – I need a few months to let the idea brew – perhaps until I see a purpose for it – and then go back to it. It just seems to reinforce that learning is best done on an ‘as-needs’ basis. Make it relevant, authentic and interesting.