We discussed the difference between reversible and irreversible changes. Then, we carried out three observations to look at these more closely: heating an egg, adding water to mod-roc and mixing bicarbonate of soda with vinegar. We thought about what the materials we like at the start and then how they ended up when they went though a change.
This week, we learnt about filtration - the process used to separate an insoluble solid from a liquid. Firstly, we mixed soil and water together to create a mixture. Then, each table got a different filter to pass their mixture through: paper towels, cotton wool pads, a coffee filter, filter paper, nylon and muslin. We compared the success of the different filters, depending on how clear the water was at the end. It turned out that the paper towel was the best filter - we concluded that this was because it had the smallest holes, meaning it allowed the least soil particles through.
We have been focusing on mixtures in science. This week, we looked at dissolving - what happens when a soluble solid is mixed with a liquid. We learnt that the solid doesn’t disappear, but has simply mixed in so well that we cannot see it any more. Working in groups, we dissolved sugar in some water, and each changed a different factor (temperature of water, amount of sugar, type of sugar etc) to understand what affects how well sugar dissolves in water.
In this lesson, we learnt about refraction. This is when light moves from the air and passes through a transparent object, such as glass or water, and it bends. We saw the effects of this by putting a pencil in a glass of water - the pencil looked like it was bending, due to the refraction of the light.
In term three, our science lessons are focusing on light. After learning about how light enables us to see, we focused on how we see different colours. In order to explore this concept further, we conducted an experiment, where we used different coloured filters to shine a light on different colours. We discovered that the red colour reflected the red light, appearing red, whereas the blue and green absorbed it, meaning they appeared black.
This term, our topic is space. To start off, we learnt about the planets in our solar system: their order, sizes and orbits. In order to make a comparison, we were given different objects, and had to guess which object represented each planet - their sizes were based on imagining the sun was as big as a beach ball. We then went up on to the playground and measured their distance from the sun, imaging that it was just 10cm in diameter. We were shocked by the distances!
In our science lesson this week, we learnt about the reason behind night and day: it is all to do with Earth’s rotation. To explore this idea, we used torches and sport balls to model this process.
This week, we have learnt about the moon. To help us to understand why we see different parts of the moon at different times, we role played the role on sun, moon and earth in groups. This helped us to see that the part of the illuminated side of the moon we can see at any given time changes, due to where the moon is in the sky.
We conducted an experiment to see how the surface area of the blades on a spinner would affect the time it took it to fall. We found out that the smaller the blades, the quicker it fell - this is because there was less air resistance acting upon the smaller surface area.
This week, we looked at parachutes. Each group had to choose a variable to change and investigate its effects.
We have been learning about friction. We conducted an experiment to test which shoe had the best grip (therefore, which produced the most friction) To do this, we used Newton meters to measure the force required to move different shoes - the ones that required us to work harder to move them, produced the most friction and had best grip.
In our science lesson, we investigated levers. In order to do this, we created our own, using rulers and pencils. At one end was a load, the other a force to lift the load. As we moved the fulcrum, it was interesting to see how the amount of force required to lift the load changed. We found out that the closer we got to the force, the more force it required to lift the load. Therefore, levers are useful to make a little force have a greater affect.
We investigated pulleys and how they can affect the amount of force required to lift a load.