bacteria puzzle 7y1 (no prizes now – unclaimed!)

a scientist is experimenting with bacteria that are one micron in diameter and that reproduce by dividing every minute into two bacteria. at 12:00pm, he puts a single organism in a container. at precisely 1:00pm, the container is full. at what time was the container half full?
bacteria 18 answers in and here are the 10 winners: callum arthur, lois keeler, jordan morton, hannah thomas, megan wilson, amber clair, callum ebbs, luke hillan, megan downey, and sean burrell. collect your prizes after half term!

making bread in a microwave

1. Mix one teaspoon of sugar into half a beaker of warm water (37C).
2. Add one dessert spoon of yeast and mix.
3. Leave on a warm radiator to froth up. Say 10 mins
4. Weigh out 300g (a plastic coffee cup level is about 100g) of flour and add one teaspoon of salt and a dash of oil.
5. Add the yeast mixture and just enough more warm water to get a stiff dough.
6. Knead on a floured board until elastic not sticky.
7. Form into little buns and allow time to rise a bit.
8. Bake in a microwave for 3 minutes, one minute at a time.
9. Eat. Note the bread will not brown unless you bake it in a proper oven.
Ingredients: sugar, yeast, flour, salt, oil, microwave, board, bowl, teaspoon, dessert spoon, warm radiator, beaker

year 11 btec fertiliser project

you should be able to complete this project over two lessons.
you need to find out about how fertilisers are made.
answer the following questions by following the links:
1. what are fertilisers? link
2. why are they used? link
3. how much fertiliser is used in the uk each year? link
4. what is ammonia? link
5. how is ammonia made? link
6. draw and label your own picture of the process used to make ammonia. here are some possible pictures to use.
explain the following:
7. why is the process carried out at 400-450°C? link
8. the trays inside the main reactor are made of iron. why is iron used and what does it do to the reaction? link
9. the iron trays are made of iron mesh, not iron plates. why would this be better?