### Archive of ‘Science 7’ category

Our group’s question was “How does the heart rate change with ages of people with exercise?”. This question was quite easy to come up because there was a website which had ideas of questions. Me and my partner both like sports so we went to the sports section and there was a question about heart rate at the start of the section.

The procedure and the documentation was helpful because there were questions we were supposed to answer and those questions helped us research and get the results of our question.

I think I worked well individually because I answered the question on the document alone and me and my partner had each part so we can divide the work equally and I did my part well!

Next time, I would use a poster because when I was talking in the video, I couldn’t really hear my voice clearly. Also next time I would do it individually and I want the experiment to be the one I can work by myself.

I learned that conducting scientific investigations is quite hard and there are lots of errors we need to face too. Which also means that before we start the investigation, we need to plan well so we won’t have that many errors.

Question: How does the light bulb in a circuit work?

Answer: Charges come out from the negative terminal of the battery. Inside the charges, energy is stored. Charges are inside the wires and when the switch is turned on, the charges move in a certain pace. There are lots of charges inside the wire in a single line. When the charges come to the light bulb, the light bulb transforms electrical energy to light and heat energy.

Our experiment was to find the percentage of salt and iron from the loromite which is a rock. However, loromite isn’t made with only salt and iron. There are cement and other stuff in it too.

These are the equpiments you need:

filtering paper, bunsen burner, beaker, water, pestle, calculator, balance, rock, tripod, heat proof mat, scrap paper

1. First smash the rock with the hammer. Then with the pestle.

2. Then measure the mass by putting it on the scale.

3. Put the rock in the beaker that has water in it.

4. Mix it so the salt will dissolve.

5. Next, filter the liquid inside the beaker little by little. Make sure the liquid will go into the flask which you set.

6. Then, evaporate the water that was filtered by using the bunsen burner. At this point, put the liquid in the beaker, not the flask.

7. Measure the mass of the salt and iron.

8. Find out the percentage by salt=mass of salt/mass of the rock x100; iron=mass of iron/mass of the rock x100.

9. Write down the result and other information on your blog or somewhere you can present them.

The result was

The mass of the loromite: 26g

The mass of iron: 11g

Cement: 10g

Salt: 5g

Percentage of iron= 42%

Percentage of salt= 19%

I think there were quite a lot of errors during our experiment. The first one was that when we were filtering, we couldn’t filter all of the liquid because the cement and iron was stopping some liquid. The second error was that when we were measuring the mass of salt and iron, some iron were stuck on the filtering paper, and as I said above, some liquid wasn’t filtered so we couldn’t weigh the perfect amount of salt since the liquid will be the salt when it evaporates. The third error was that when we were smashing the loromite, the loromite scattered in various places. There were more errors but these were the three main errors.

I think we did okay for our experiment but I think we can improve our experiment by having less errors by overcoming our errors. However, I enjoyed the experiment and next time I would like to have the mass more accurate.