Put different objects, such as coins, paper clips, gravel, buttons or rubber bands, inside different bottles. Paint the outside of the bottles so that the children cannot see what is inside. Encourage them to shake the bottles and guess what is inside. Later, open the bottles to show the children whether their guesses were right or wrong.
Use liquids of different densities to fill your bottle, such as water and cooking or body oil. You can add a few drops of food coloring to the water. After shaking the bottle, the children can observe the formation of separate layers. Alternatively, you can fill up different bottles with different materials, such as hair gel, water or oil, and insert some colorful marbles. Children can explore the diverse ways marbles move in each bottle when shaken. Add glitter to create an extra colorful effect.
Cut plastic bottles in half. Paint the outside of each half bottle using black paint. Select materials of different textures, such as cotton wool, scouring pad, sand paper, bath sponge, satin, wool and other types of fabrics. Glue a piece of a different material on the inside of each half bottle. Cut the toe area off of old socks. Glue an extremity of the sock around the rim of the half bottle in order to hide the material you placed inside it. Encourage the children to put their hands through the sock and describe what they feel when touching the mysterious material inside the half bottle.
Explore hearing and sight at the same time by making a tornado bottle. Place water, soap and a marble inside a transparent plastic bottle. When children shake the bottle, they can hear the rattling of the marble and observe a mini tornado. Create a "rain bottle," by putting uncooked rice and toothpicks inside a bottle. Leave about half an inch at the top and close with the cap. Ask the children to turn the bottle upside down. The rice falls through the toothpicks, making a sound similar to rain.