Phew!

We finished the third and last Stepping Stones evening on Thursday. Boy, was it hard work. A circus of 17 Physics kits set up in two labs, 2 small class pracs and one big one involving laptops and Logits and finished off by some classic physics demos. The agar plates from last week were on display – half of them had an assortment of colonies on them which was far more interesting than last year when everyone had excellent aseptic technique! But it was excellent. Everyone was challenged but pleasantly so and the feedback was great. It’s been good for us techs too, each of us brushing up our skills outside our usual area of responsibility. Perhaps more importantly, in the process of explaining to novices about the apparatus and experiments, we’ve learnt such a lot. It’s because you are forced to think more clearly and in a more focussed way in that situation. I also have to report that we understand better the problems our teaching colleagues have when running practicals or teaching a lesson!
The one hitch we had was, yes the IT technology. The laptops were fine, we chose the most up-to-date, set them up and had them logged into the wireless system and software loaded well before the start time and checked all the sockets were on! I also checked all the Logits and temperature probes were working and the battery symbols were reading full. Despite all that, 1 probe and one logit has system faults and two logits died. We had two spares available and we had to sacrifice the one attached to the digital OHP and lead purely by referring to the participant instruction sheet and vocally (thank goodness for P for this, who has a powerful voice - we do a bit of a 'Little and Large' act).
Anyhow a resounding success. I really appreciate and am grateful for all the enthusiastic work and input from everyone on our science technician team, and it's been really enjoyable working with them all on this project and I think they have all enjoyed it too despite all the work. I now have loads of photos and notes to post onto the Course website for the third and last evening, which is a pretty time consuming process but provides a very useful record for all of us as well as a means of follow up for the participants.

Yr12 Back, Marble Chips and the School Science Technician Role

Yr 12 are back and with a vengeance – starting the practical-heavy part of their A2 course before the students or teachers are whisked away to participate in all the end-of-year expeditions and events like the World Challenge Expedition, Do E, Yr7 nature reserve trip, Yr12 Essex Uni Chemistry and DNA all-day workshops, etc…

In chemistry it is the nitration of methyl benzoate which is an exercise in preparing a chemical product, purifying it and assessing its purity with melting point apparatus. P and I have a pact between us to empty the ice maker every chance we get in order to keep the freezer full as the nitration process makes heavy use of ice baths and crushed ice for crystallisation. We still haven’t found a satisfactory affordable machine for the latter, the device we use only takes 7 ice cubes at a time – slow!

The first two days of the Stepping Stones course have gone very well, everyone seems to enjoy themselves and this year we actually got through all the prepared practical activities. We achieved this by preparing beforehand all the constituents and doing some of the activities like the acid/base titration step-by-step and led from the front, Me on one side and P on the other, Little and Large!

‘Ah, but that’s not what science technicians do’, I can almost hear my imaginary readers say, ‘we just get the stuff out and wash up’. Well that is certainly true when things are busy (which is rather a lot of the time) and during a new science technician’s first year when they are learning the ropes. After that, we try things out.

An example. In the set up above, which is for a classic GCSE rate of reaction investigation, the purpose is to collect and measure the time taken for a fixed volume of gas to be given off when marble chips are reacted with bench dilute hydrochloric acid. Variables can be size of marble chips down to calcium carbonate powder, temperature at which the reaction takes place or more likely the concentration of the acid.

Sometimes the pupils have to find out for themselves appropriate ranges of concentration, what size measuring cylinder to use, etc. More usually they have less than hour for the practical and lesson, and we want to provide them with the ingredients that will actually give them satisfactory results and enthuse them. So, beforehand, the science technician would experiment with the plastic measuring cylinder sizes, bench HCl and other equipment available. So, say, surface area is being investigated - what amount of chips gives a reasonable result using a 100 cm3 plastic measuring cylinders, (of which we have loads)? We find the a volume of 80 cm3 is easy to read off on the inverted measuring cylinder. We also find that constantly swirling the conical flask once the stopper is in each time is the only way to get consistent and reasonable results. We also find that too large a quantity - the small chips react too fast to be controllable, use too small a quantity - and it takes over three minutes to get the 80cm3 of gas. The best results are with 2 grams of each size of chips which results in about 30secs with the small chips and 90secs with the large chips to produce 80cm3 of gas. That aspect of rate of reaction, surface area, can now be investigated successfully by the class in half an hour leaving time for the write-up theory and of course clearing up. DON’T forget the sieves and reminder to avoid the curse of the science technician’s work – BLOCKED SINKS!

Stepping Stones

The Stepping Stones course started last Thursday. It comprises three 2.5 hour sessions on three consecutive Thursday evenings. I try to keep the talking to a minimum to allow the maiximum time for practical activities. Each attendee has a ring binder with material referred to both from my introductory presentation and the activities as well as access to a course forum that I have set up with a lot of the same material and extra information and useful links. I've used a course area on the school VLE (Virtual Learning Environment) and made it private to the course attendees and the school science technician team. I've opened a forum facility within it as well as a message/chat facility and Quickmail. There is so little time to get everything across and this is my way of enhancing the time available. It has been an awful lot of work and I'm reallly pleased when an attendee actually posts. I think many of them are not accustomed to forums and the like, as well as having little if any experience of working in a secondary school or lab, so it's probably asking a lot of them. I've had some really encouraging responses and that keeps me going!

As well as all the prep for the above, the raw unroomed timetable has just plopped into my email. We're starting a two week timetable in September. First impression, not too bad, afternoons lighter than expected. Closer inspection - ugh - it's going to be much more complicated making sure the groups and teaching staff all have their fair share of timetabled labs rather than classrooms. It will take most of Monday for sure!