Recent content by A Walter

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    CLOSED - Senior Technician, Watford TTO+2

    I'm going into teaching so my job's up for grabs. I'm teacher teaching at the same school. https://www.tes.com/jobs/vacancy/senior-science-technician-hertfordshire-1183300 Closing date 29/03/2019
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    Iodine in acrylic burette

    Hi Everyone! We've 'invested' in some acrylic burettes because I'm fed up of kids smashing them. But what can't go in them? I know tomorrows propanone is a big no-no but how about iodine solution in KI and water? Will they stain or will it rinse through? Cheers!
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    Monkey and hunter

    In case others have trouble with a thin strip of aluminium not being broken (as I used to) you can also attach a wide piece of aluminium to a thin wire so there is a manufactured weak point. We used to use an air rifle which would just push/bend the aluminium foil out of the way.
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    Techs as Demonstrators

    Well I've said yes to HoD so I'll try to remember to feedback. Class demonstrations is already in my job description.
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    Techs as Demonstrators

    My HoD has forwarded this course to me: https://www.stem.org.uk/cpd/424271/technicians-demonstrators I saw it last academic year and dismissed it for the time taken. But with HoD suggesting it I'm taking a closer look. Has anyone taken this course? If so, what did you think? Did it make any...
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    Slime Warning

    Don't worry I'm not here to scaremonger about how slime made from evil borax will eat your children. I'm here to warn (scaremonger really) those that, like us, are making slime as end-of-year or summer school activities. Perhaps steer clear if possible, use the not borax free CLEAPSS method, or...
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    Resistor 'roulette' safety

    Hi Everyone! In my ongoing quest to make physics interesting to those who don't like maths I've 'been inspired by' Big Clive of YouTube fame to make electrical calculations interesting. So my premise is a board of resistors connected in parallel to a large voltage source (9V batteries in...
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    Colourimetry I2, H2O2 & Acetone

    Hi Everyone, I can't find a practical (probably because I can't remember enough about it). Colourimetry is used, I believe to determine rate, using iodine, hydrogen peroxide and acetone. Might be wrong on the iodine part, but I do remember the colour measured was blue-black. Definitely not a...
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    Quickfit glassware quality

    Hi Everyone, It's ordering time! And the budget is tighter than an otters pocket. Or is that wetter..? Anyway we're looking at distillation/reflux apparatus for OCR A lvl chemistry. Due to our lack of apparatus our chemists usually enter AS a little green and the first distillation lesson...
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    Tips on DNA extraction

    I've just trialed this with an ice bath, ethanol and salty water mouthwash worked alright at first but upon standing lots more DNA precipitated out. Salty mouthwash tasted disgusting, and I'm now realising we're doing this at lunchtime :confused: Will have peas on hand for those that would...
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    Voltmeter is parallel

    The fact they have continuity is a miracle the way they're treated!
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    Voltmeter is parallel

    I was a class yesterday and a student produced a circuit that perplexed me, I'd never come across the setup before. Simply put he had a battery (1.5V), voltmeter, ammeter and two bulbs (1.5V). The bulbs were in parallel, one of them in series with an ammeter. The single voltmeter was in parallel...
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    Tips on DNA extraction

    I've heard somewhere that you can blitz the peas in a blender initially to increase yield, do you do this? (Or am I thinking of a different extraction?)
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    Tips on DNA extraction

    Hi Everyone! For our next science club we're going to extract DNA to make little pendants, and I mean little, maybe 1ml at most! With that in mind, what little tips and tricks do people use to extract the most DNA possible from cheek cells? Some I've heard so far Salty mouthwash. Ice cold...
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    Bromine gas

    I'm gonna try this now as I need it tomorrow morning. Do you use an amber flask?
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