This year, the students of the 4th grade of the elementary school Hugo Badalić from Slavonski Brod, Croatia will join the STEM Discovery Campaign 2022. with the topic Not every water is H₂O. In the conducted activities, the students used the skills of observation, measurement, observation, graphical presentation of data, inferences, and the activities marked the World Water Day.

At the beginning, the students answered the questions What does water look like? What shape is water? What does water smell like? What does water taste like? What is water for? How important is water to us? What do we use water for? What would happen if we didn’t have water? They repeated the acquired knowledge about water circulation in nature.

In the first activity, students learned that there is 71% water on Earth and the rest is land. They showed this percentage by filling the squares with color (blue percentage of water, and brown land). They found out that out of this 71% of the water surface, as much as 97% is salt water, and only 3% is fresh water, and they showed that ratio by filling in the squares.

In the next activity, they researched on the Internet that the human body contains as much as 70% water, and they also showed that percentage graphically by filling that percentage of the body with color.

The students listed which animals live in water (fresh or salty) and made a graphic presentation of the number of animals shown on a piece of paper.

We also mentioned the beaver which also lives in the water. On the CodeMonkey programming platform, students helped the cheerful beaver with sequence, branching, and repetition commands to complete the dam and make cocktails for his friends.

For the Running Water activity, we prepared six glass cups, different food colors, paper towels and, of course, water. The students filled three glasses to half full with water and added 5 drops of food coloring. They arranged the glasses in a circle so that every other glass was empty. They took a paper towel and folded it into strips and placed it over the edges of the cups. The water slowly moves towards the paper towel through a process known as capillary action. The paper towel is made of fibers and water can travel through the gaps in the fibers. These voids act like capillary tubes, pulling water upward. Students compared this process to watering a plant, where water travels from the root of the plant to the leaves at the top of the plant or tree.

For the Colorful Rain in a Glass activity, we prepared a larger glass cup, an oil cup, edible oil, food coloring and water. The students filled a larger glass with water up to 3/4. They carefully poured the oil into another glass to a height of about 2 cm, and then carefully added food coloring of different colors to the oil. With the help of a wooden stick, they broke the food coloring into small drops. Oil and drops of food coloring were poured into another glass and they were surprised by the result of the experiment. They noticed that water and oil did not mix, and that drops of paint fell slowly, like colorful rain, to the bottom of the glass. They learned that water, although they claimed otherwise at the beginning of the experiment, has a higher density than oil.

For the activity Melt, don’t melt! we prepared six glasses and sugar, salt, pebbles, soap, paper, eraser, and of course, water. The students added 100 ml of water to each glass, and sugar to the first glass, salt to the second, a piece of paper to the third, a pebble to the fourth, soap and a rubber to the fifth. After that, they observed what of the above dissolves in water and what does not.

For Hot or Cold activity! we prepared water, four glass cups, different food colors, a kettle. The students filled four glasses: one glass to the top with cold water, one glass to half cold and half hot water, one glass up to a quarter with cold water and three quarters with hot water and one glass to the top with hot water. Add a few drops of food coloring to all the glasses and watch what happens in the glasses. They concluded that the paint dissolves faster in hot water and became acquainted with the concept of diffusion, ie spontaneous mixing of substances with their environment.

For activity Thicker than you think! we prepared a larger glass, edible oil, water and honey. The students filled a glass with one third of honey, one third of water and one third of oil. They observed how three layers were formed, depending on the density. On the Internet, they found that the density of a physical quantity is characteristic of each substance and is equal to the quotient of the mass and volume of that substance.

The students enjoyed today’s activities and learned something new about water that they did not know until now. The activities of the international eTwinning project Full STEAM ahead were also carried out.