P2 Chapter 7 Revision – Where do the elements come from?

Professor Brian Cox – teaching you GCSE Physics 2…

The Big Bang made hydrogen – but where did the other 91 natural chemical elements come from? These clips from the BBC’s Wonders of the Universe by Brian Cox answer the questions…

How do we know there are only 92 elements – even out in deep space?

All atoms give out only certain colours – a spectrum – based on how their electrons behave. They also absorb only those colours too. You might have seen this by doing flame tests or looking at gas discharge tubes using a spectroscope.

How did all these elements get made?

Every element in nature was made in stars, during their “life and death” by a process of nuclear fusion which gives out energy up to Iron (so these are made as stars live and die) but needs energy for heavier elements (which means these are made when a star explodes)

Not little stars like ours – but HUGE stars!!

Mr G

Sources: BBC Wonders of the Universe

Long time – no see…

Well – it’s been a lot longer than I thought since the last post – yet still a surprising number of visitors in the last 30 days and from all over the world.

Screeny Shot 19 Feb 2013 11.04.17

 

I hope to get back to writing ASAP and maybe rope in a few more student bloggers to keep up the pace.

Mr G

Tribute – to the coolest geek in the world…

Enjoy…

Mr G

 

Keele Observatory Trip

Finally, a spare moment to get the photos from my camera…

Enjoy the slide show.

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Mr G

Welcome to the Anthropocene – What now?

The current epoch of time is called by many the Anthropocene. The time of mans impact on the natural world.

This video shows how dramatically our impact on the world has changed since the industrial revolution.

This BBC News article introduces the effects we have had and the views of scientists as to whether we can survive this era.

The Earth system will stabilise again, but under a different set of conditions, which would be a lot less suitable for the whole range of nature that we find today – Professor Will Steffen

Mr G

Sources: BBC News, Vimeo.

Physics Revision Videos – AS Unit 1

Below are the topics of AS Physics – Unit 1.

Where possible links to videos (e.g. Khan Academy) have been added – more will be added over time – Units 2, 4 and 5 to follow

Mr G

AS Unit 1

HFS

EAT

  • Density
  • Laminar and streamlined flow
  • Turbulent flow
  • Viscous drag
  • Upthrust
  • Terminal velocity
  • Stoke’s Law
  • Viscosity and temperature
  • Elastic and Plastic deformation
  • Brittle
  • Ductile
  • Hard
  • Malleable
  • Stiff
  • Tough
SUR
  • Force-extension graphs
  • Limit of proportionality
  • Elastic limit
  • Yield point
  • Hooke’s Law
  • Stiffness
  • Tensile & compressive stress
  • Tensile & compressive strain
  • Breaking stress
  • Young’s modulus
  • Elastic strain energy

Link Key

K – Khan Academy – Physics

Khan Academy – Science Revision 2012

I first mentioned the Khan Academy back in 2010. It is even bigger now, over 3000 videos and much more famous. For those of you with an iPad there is even an app so you can download the video clips for viewing offline.  Now they have an iTunes U page too for iTunes and the iPad iTunes U app.

Over the next few days/weeks I’m aiming to find videos for each unit of A2 and AS Physics (and show Biol and Chem how to do theirs too…) After that I’ll be working through the GCSE Physics courses from the New P1 upto Old P3.

‘White snake’ seen on the surface of Mars

Image

Actually it’s a dust devil – a mini tornado… But this is a brilliant photo taken by the NASA Reconnaissance Orbiter.

Mr G

Sources: New Scientist, NASA, Wikipedia

Energy Drinks – the effects on students…

I’ve not blogged for a while – so I’m starting again with something we as teachers are getting concerned about.

These last few years energy drinks are increasingly popular with youngsters. Advertising, sponsoring big events have made energy drinks a “Monster” of a problem in schools.

Red Bull was probably the first really popular energy drink. High in sugar and as much caffeine as a strong coffee, the 250ml cans perked you up and massive sales ensued (Red Bull now have enough money to sponsor a wide range of sports – including 2 F1 teams)

But the craze has spread and the cans have gotten bigger and so has the problem.

Members of the team would often complain of feeling dizzy, shaky and hyper during practice; sometimes they’d vomit in the middle of a workout. It was directly related to their consumption of energy drinks – Coach of Midlakes High School swimming team

Energy drinks are not the same as Sports Drinks – energy drinks contain large amounts of caffeine. Energy drinks have “no therapeutic benefit” where as some sports drinks do. Most people would not guzzle several strong coffees in a quick succession – but that is the same as drinking a 500ml can of energy drink.

They may harm the health of children, especially those with diabetes, seizures, cardiac abnormalities or mood and behavior disorders. Energy drink overdoses in children as young as 5 have been reported both here and abroad and in some cases have resulted in seizures, stroke and even sudden death.

Whenever I see students drinking these drinks I point out the warning “Not suitable for children”. Teachers often see the effects of students drinking energy drinks between lessons – brought into school by the students. Partly to blame is the marketing.

More than half the market is under 25 years of age and 30-50 percent of adolescents and young adults consume energy drinks. A quick perusal of packaging, websites and marketing material for the beverages shows they are clearly aimed at the youth market.

We learned far too late the effects of smoking on addicted teenagers – is this the start of the next big health issue?

Children, or other people sensitive to caffeine, should only consume in moderation drinks with high levels of caffeine – UK Food Standards Agency

Mr G

Sources: ABC News, Medical News Today, The Daily Mail, NHS.

A Month of Spectacular Space Weather

The Sun has been pretty busy lately, with lots of flares and coronal mass ejections sending high energy particles flying towards the Earth. These can cause problems, both in space and on the ground.

Fortunately the Earth’s magnetosphere deflects most of these away from us. But the field comes back to Earth at the poles and these high energy charged particles come rushing down into the atmosphere (in some cases accelerated by the Earth’s magnetic field).

These particles “excite” the atoms in the air by giving the atoms electrons more energy, which then get rid of the energy again as light. Blue or Red for nitrogen (70% of the air) and Red and Green for the oxygen.

At high altitude oxygen red dominates, then oxygen green and nitrogen blue/red, then finally nitrogen blue/red when collisions prevent oxygen from emitting anything. Green is the most common of all auroras. Behind it is pink, a mixture of light green and red, followed by pure red, yellow (a mixture of red and green), and lastly pure blue.

Just like iron filings line up along a magnetic field, so do the charged particles. We get sheets of air glowing when hit by the particles following the Earth’s field lines, drifting and swirling around. We call them Aurora. Aurora Borealis (a.k.a. The Northern Lights) and Aurora Australis (The Southern Lights).

Here is a BBC Stargazing Live video explaining Aurora – it’s aimed at Primary kids so it’s kept nice and simple.

Below is a slide show of Aurora photos taken during January 2012.

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Mr G

Sources: Wikipedia, BBC News, BBC Stargazing Live, Various Newspaper websites.