# Physical science

## Cotton (the one we use for medical purposes)

Take 1 ball of cotton in your right hand and show it to the baby. Say: look, this is a cotton ball. Cotton ball! Touch it. Take 2 other cotton balls and place them into the baby's right and left hands. Describe the feeling of touch. Say: the cotton balls feel so soft, fuzzy & fluffy, downy. They also feel warm. They are so light!

sound: Prepare in advance a cutting board and some cotton. Say: let's listen to what sound the cotton 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 cotton ball will create. Take the cotton ball in your right hand and let it drop on the cutting board. Say: can you hear the sound? It seems the cotton ball is so light, that almost no sound is produced by it! Let's do it again! Put the cotton ball in the baby's right hand and let the baby try to squeeze it. Say: can you hear any sound?

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 cotton ball is elastic. We will make an experiment. We will bend the cotton ball and see if it will deform. What do you think will happen to the cotton ball? I think it will not deform just a little bit. Now let's conduct an experiment. Take the cotton ball and squeeze it in your right hand. Place another cotton ball in the baby's right hand and let the baby squeeze it too. Help if needed. Observe the cotton ball. Say: I see the cotton ball got a little smaller, deformed, but it did not break. Hence we can conclude that cotton possesses some elasticity. Plasticity can be tested in the same way. If after bending the object retains the new form without rupturing or breaking, it means it is very plastic. Our cotton ball has some plasticity also, because it became a little bit smaller.

Hardness. Say: I wonder if cotton is hard. When we say the object is hard, we mean next: 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 cotton is hard? Let's make a hypothesis. I think it is not hard. Let us conduct an experiment in order to prove or disprove out hypothesis. We will need a coin for that. Place a piece of the cotton on the cutting board holding it by your left hand and take the coin in your right hand. 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 cotton with the coin. Do that. Say: let's observe now. What do you see? Do you see any holes left on the surface of the cotton? Did the surface get deformed? Yes. It did. It means the cotton is a soft object, not hard..

Let’s explore if cotton is waterproof and absorbent. A material is waterproof when it repels liquids. What do you think about cotton? Is it waterproof? I think it is not. Now let's make an experiment to prove our hypothesis. Take a large pot. Put a jar/cup into it. Put a piece of cotton on top of the jar/cup so it will cover the opening like a lead. Say: let’s observe. Poor water on the cotton. Say: the cotton is not waterproof; water can go through cotton 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 cotton? See it soaked up some water. Let’s squeeze the cotton now to see how much water got into it. Squeeze it. Say: see, there is some water coming out of it. The cotton is absorbent.

Since the water is here, we will add some more of it and check out if dry cotton floats or sinks. What do you think will happen to the cotton when I put it in the water? Let's make a hypothesis. I guess the cotton will float. Say: Let’s test it now. Put a piece of dry cotton in the water. Describe what you see: I see that the cotton floats. It means that density of the cotton is lower than density of water.

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 cotton is ductile. 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 cotton stretched a little bit and then broke! It is not ductile. It tears down and can’t be stretched into a wire.

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

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