# Physical science

## wooden spheres in a box/jar

sound: Prepare in advance a transparent plastic jar and several wooden balls/spheres. Say: let's listen to what sound the spheres will make. Remember that soundwaves are created when some energy is applied to the object. Then molecules of the medium start moving pushing other molecules, making them vibrate. That’s how the sound is created. Let's listen to the sound that the spheres will create. Take the spheres in your right hand and put them in the jar, one by one, so the sound can be heard. Then close the jar and shake it well. Make sure there is at least half of the space empty in the jar. Say: can you hear? Open the jar and put the baby's hand into it. Help the baby mix and stir the spheres in the jar and listen to the sound they produce. Then close the jar, place it in the baby's hands and help the baby shake it. Say: listen to the sound! It is so loud!

elastisity and plasticity: we know that elasticity is ability of the object to retain its size and shape after removing the force that is applied. If the object does not deform, it is considered very elastic. Let us see if the wooden spheres are elastic.Pick up the solid. Say: it is a sphere. It is a solid. It is all round, like a ball. We will make an experiment. We will try to squeeze the sphere and see if it will deform. What do you think will happen to the shere if we squeeze it? I think it will not deform at all. Now let's conduct an experiment. Take the shere and try to squeeze it in your right hand. Say: it is very hard to squeeze it. It is impossible, I am not strong enough! Place the shere in the baby's right hand and let the baby try to squeeze it. Help if needed. Say: can you see? We can't squeeze it. We can conclude that wooden sheres are not elastic at all. Remember, that plasticity can be tested in the same way. If after squeezing the object retains the new form without rupturing or breaking, it means it is very plastic. Our spheres are not plastic, because they do not bend.

Hardness. Say: I wonder if the material the spheres is made of is hard. When we say the object is hard, we mean that when I scratch it with another sharp object there is no sign left on it. It is very difficult to leave traces on it. If the object is hard it means it is resistant to permanent shape changes. Do you think the wooden sphere is hard? Let's make a hypothesis. I think it is hard. Let us conduct an experiment in order to prove or disprove out hypothesis. We will need a coin for that. Take the wooden sphere in the left hand and the coin in the right. Make sure your hands are in front of the baby's face so he can see well what is happening. Say: let's scratch the sphere with the coin. Do that. Say: let's observe now. What do you see? Do you see any lines left on the surface of the sphere? I see no lines. It means the sphere has a hard surface.

Let’s explore if the wooden ball is waterproof and absorbent. A material is waterproof when it repels liquids. What do you think about the ball? Is it waterproof? I think it is. Now let's make an experiment to prove our hypothesis. Take a large pot. Put a jar/cup into it. Put the ball on top of the jar/cup wodden part up so it will cover the opening like a lead. Say: let’s observe. Poor water on the ball. Say: the ball is waterproof; water can't go through the ball into the jar/cup. What is absorbancy then? It is ability of any material to soak up the water, right? What do you see happened to the ball? See if it soaked up some water. Let’s try to squeeze the ball now to see how much water got into it. Squeeze it. Say: see, there is no water coming out of it. The ball is not absorbent.

Glossy/mat: Say: The (object) is shiny/glossy/mat. (glossy - reflects the light, mat - absorbs the light)

Brittleness: DO you think the (object) is fragile? Make an assumption. The characteristic for fragility is brittleness. We will drop the(object) from up to the ground and observe if it breaks. Let’s do an experiment. (Take an (object) and drop it from stretched high hand). Say: look at the (object), it did not break at all! It is not brittle. Or it broke and it is brittle.

Magnetic: Let’s see if it is magnetic. We will get a magnet and put it close to the (object). See: the (object) is on the same place. It does not move so it is not magnetic.

Transparent, translucent, opaque: Hold the (object) in your left hand in front of the baby and say: (baby's name),do you think (object) is see-through? Le's make a hypothesis. I thinks it is. Now we have to make an experiment to prove or disprove it. We will need a dark room and a flashlight. Make the room darker or go to the dark room. Place the object in the left hand and the flashlight in the right hand. Switch the flashlight on and say: let's observe if the light goes through the (object). Say: I can see some light passing through the leaf. It is translucent. (If your leaf is thick – you cant and then the leaf is opaque).

Fluid.Now we will see if the (object) is fluid. My hypothesis is that it is not. We will conduct an experiment in order to check it out. Hold the (object) in your right hand with two fingers if possible. Say: Look! I am holding it and it does not change its shape and does not move at all. It does not flow.

Soluble: Let’s see if it is soluble. What do you think, is it soluble? I guess it is not. Let's again make an experiment and check it out. We will need some water. Take an empty bowl, pour some water into it. Put the leaf into water again. Say: look the leaf does not dissolve in the water. It remains as it is. It means it is not soluble.

Insulator: If we put a lot of leaves together in a pile, they will be a good insulator. They will keep warmth inside.

Burn: (object) contains oxygen molecules and can burn with high temperatures. (explain about your object)

Let’s check if the sphere is made of a ductile material. Let us try to stretch it and observe if it becomes a wire.If it does, then it is ductile. Start stretching. Say: see, the sphere is very hard to stretch! It is not stretchable at all. Hence It is not ductile.

Our (object) smells so fresh and nice! Or describe how it smells

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