Explore a magical world with your kids at home – 15 awesome science experiments!
1. Color-changing flowers
Material preparation: white carnations, food coloring, water, cup
How to make:
(1) Pour the same amount of water into the cup, and put a few drops of food coloring into one of them
(2) Put the flowers into transparent bottles, and observe the change of the color of the flowers after a few days.
Scientific knowledge: The stem is one of the vegetative organs of the plant, which has the function of supporting the plant and transporting water and nutrients. The stem of the plant transports the water and nutrients absorbed by the roots to the various parts of the plant from bottom to top. The flowers in the vase change color precisely because the stems conduct the blue ink.
2. Inaccessible balloons
Material preparation: two balloons, dry flannel (or fluff), thread.
How to make:
Blow up two balloons, tie them to prevent air leakage, and connect them with thread.
Scientific knowledge:The electricity charged by objects due to friction is either positive or negative. The same charge as the glass rod rubbed with silk is called positive charge; the same charge as the rubber rod rubbed with fluff is called negative charge. Identical charges have the property of repelling each other, while different charges attract each other.
Since the two balloons have the same charge after being rubbed by the fluff, they will repel each other and naturally separate.
3. Battery family
Material preparation: various types of batteries, electric toys, a battery family map.
(1) Let the children observe the appearance characteristics of the battery, and classify or queue the batteries according to the model and function.
(2) Guide the child to choose the appropriate battery, put it into the electric toy in the correct way, and make the electric toy move.
A battery generally refers to a small device that can generate electricity, such as a solar cell. The chemical batteries we usually use can be divided into primary batteries and accumulators. The primary battery can generate current after it is made, but it is discarded after discharge. The accumulator is also called a secondary battery, which can be discharged after charging, and can be charged and reused after discharging.
At present, our general disposable batteries mainly include carbon batteries and alkaline batteries. Generally, each section is 1.5V and is cylindrical. The common models are A,AA, AAA . The larger the number, the smaller the model. When we correctly install the battery into the electric toy and turn on the switch, the battery can provide current to the circuit. At the same time, the electric energy is transformed into mechanical energy, and the toy can move.
4. Magnetic field lines
Material preparation: a small plate, a plastic bag; a piece of paper, some iron filings; a bar magnet.
1. Put the magnet in a plastic bag, then stir it in the sandpile, then take out the plastic bag and put it on a small plate, take out the magnet, the iron filings will fall off, and after many times, you can get a lot of iron filings.
2. Put the magnet on the handmade paper, evenly sprinkle the collected iron filings around, tap the paper lightly, and due to the action of the magnetic field, the pattern of magnetic lines of force will appear on the paper.
5. Beautiful rainbow
Material preparation: two plastic water bottles, a compass; an awl, some water; a needle.
1. Use a needle to poke about twenty small holes in the plastic bottle cap, fill the plastic bottle with water, and close the cap tightly. People turn their backs to the sun, hold the bottle, squeeze the water gently, and then see the rainbow.
2. Use an awl to poke a hole in the other cap and repeat the above test, this time no rainbows can be seen in the light rain sprayed from the cap.
6. Water flute
Material preparation: a long straw, a pair of scissors; a milk bottle; a bottle of water.
1. Use an empty glass milk bottle and put half a bottle of water into the bottle;
2. Use scissors to cut a slit about one-third of the long straw, so that it is almost disconnected, but still connected a little;
3. Bend the straw at the incision, insert the longer section of the straw into the water, and the incision is on the water surface. Blow hard on the straw to hear the sound, adjust the position of the straw in the water, and the sound will change again.
When we blow into the straw, a jet of air is produced. When this horizontal airflow passes through the mouth of the longer straw, it causes the air column in the straw to vibrate, resulting in a faint but stable sound. As the longer length of straw descends in the water, the vibrating air column shortens, creating a higher-pitched sound, and the straw rises and the air column lengthens, creating a low-pitched sound.
7. Handmade gyroscope
(1) Decorate the disc with various sticky notes, and then insert a small wooden stick of moderate thickness through the small hole in the disc and fix it.
(2) Let the children turn the gyroscope, and then let it spin, and see who has the longest spin gyroscope.
The gyroscope is an ancient children’s toy, a revolving body that turns on the ground. When the gyroscope rotates, it not only rotates around its own axis, but also makes a conical motion around a vertical axis.
To make the gyroscope stand up, external force must be continuously applied. Once the help of the external force is lost, the gyroscope will fall down soon, because the support of the gyroscope is too small to support its own weight. The length of time the gyro rotates is related to the distance of the fulcrum from the ground, the force during rotation, the contact area between the fulcrum and the ground, and the frictional force.
8. Handmade hourglass
Material preparation: several pairs of identical water bottles (bottle mouths vary in size), sand, and a stopwatch.
(1) Two identical water bottles are grouped together, and some sand is placed in one of the water bottles. The amount of sand loaded in each set of bottles was the same.
(2) Put the bottle mouths of each group of mineral water bottles opposite each other and fasten them with transparent tape, you can make simple decorations on the bottle body, and the hourglass is finished.
(3) Invite the child to invert a set of hourglasses, observe the flow of sand, and record the time when the sand runs out.
(4) Invite the child to turn upside down several hourglasses of different sizes at the same time, and compare the different times when they are finished.
Give the sand an external force, and the sand can flow. Constantly flipping the hourglass is equivalent to giving the sand an external force, so the sand can flow. The flow rate of sand is related to the size of the hourglass bottle mouth and the number and diameter of bottle holes: the larger the bottle cap mouth, the more bottle cap holes and the larger the diameter, the faster the flow rate; the smaller the bottle mouth, the fewer bottle cap holes and the larger the diameter. The smaller the diameter, the slower the flow rate.
An hourglass, also called a sand clock, is a device for measuring time.The hourglass consists of two identical bottles, which are connected by a narrow connecting pipe in the middle. The fine sand trapped in the upper bottle slowly flows into the bottom bottle through the middle thin tube. The time required for this process can be used to measure time.
Once all the sand has flowed into the bottom bottle, the hourglass can be turned upside down to measure time. The advantage of this hourglass is that it can be used on both sides, turn it over, and the bottom can be used as the top.
9. Homemade fountain
Material preparation: two larger empty drink bottles (such as Sprite bottles), tacks, water
(1) Poke a number of small holes with the same diameter on the side of the bottle body of a sprite bottle in a vertical row.
(2) Poke several small holes of different diameters on the cap of another sprite bottle.
(3) Let the child fill the first bottle with water, the water will be sprayed from the small holes in the bottle body, and the distance of the water spray is different.
(4) Let the child also fill the second bottle with water, tighten the bottle cap, and squeeze the bottle body, the water will be sprayed from above like a fountain.
The pressure of the water is determined by the depth of the water, the deeper the water, the greater the water pressure; the shallower the water, the lower the water pressure. Therefore, under the condition that the diameter of the small holes on the bottle body is the same, the water sprayed from the bottom of the bottle is the farthest, and the water sprayed from the top is the closest. In addition, when the bottle body is squeezed hard, the water in the bottle is simultaneously affected by the pressure, and it is sprayed from the holes of different sizes. The harder you squeeze, the greater the water pressure and the bigger the fountain.
10. Homemade Bubble Water
Material preparation: washing powder, detergent, soap flakes, small spoon, water, cup.
Experimental operation: Invite the children to choose any material, put it into a water cup, stir to make bubble water, and blow bubbles to play.
Bubbles are formed due to the surface tension of water. Usually, the mutual attraction between water molecules is stronger than the attraction between water molecules and air. These water molecules seem to be stuck together, but if the water molecules are excessively stuck together, bubbles are not easily formed. The detergent “breaks” this surface tension of the water, reducing the surface tension to only 1/3 of the normal condition, which is the optimum tension required for blowing bubbles.
The proportion of bubble water will affect the effect of blowing bubbles. Generally, you can use the bubble water that is prepared with 2 parts of detergent and 6 parts of water. Glycerin is a hygroscopic liquid that combines with water to form a weaker chemical binder that slows water evaporation. So, in order to make the bubbles not disappear so quickly, you can put some glycerin in the bubbling water. Typically, the best formula for a bubble-blowing solution is: 2 parts meal wash, 6 parts water, and 1-4 parts glycerin. Through the bubbles we can see colorful light because of the refraction of the light as it passes through the membrane of the soap bubble.
11. Funny tumbler
Materials preparation: table tennis, plasticine, colored paper, watercolor pen, sand, mung beans.
(1) Cut a small opening in the table tennis ball, and stick plasticine on the bottom middle of the ball as the body of the tumbler.
(2) Make a cone with colored paper and draw the facial features as the head of the tumbler.
(3) Adhere the cone and the plastic ball with adhesive to make a tumbler.
(4) Let the child push the tumbler with his hands and observe its swinging state to see if it will fall down.
(5) Distribute table tennis balls to the children, change the weight of the plasticine and the position in the table tennis ball, observe whether the tumbler will fall down, let them understand that the lower the center of gravity of the tumbler, the more stable and balanced the tumbler will stand.
(6) Let the children fill the table tennis balls with various materials such as sand and beans, and then push the tumbler to observe its changes, so that they can understand that only when the object is fixed, it is possible to make the tumbler not fall.
The part of the table tennis ball with the plasticine sticking to it is the heaviest, so it becomes the center of gravity of the tumbler. The lower the stick position, the lower and more stable the tumbler’s center of gravity. When the tumbler is in balance, the distance between the center of gravity and the contact point is the shortest, that is, the center of gravity is the lowest, and it is the most stable. When the tumbler is pushed, the contact point between the tumbler and the table top is not on the same line as the center of gravity. After the external force is withdrawn, gravity will make it return to the position with the lowest center of gravity to maintain balance, so the tumbler will not fall no matter how much it swings.
12. Shadow Formation
Materials preparation: flashlight, doll (opaque object), glass cup (transparent object), plastic cup (translucent object), paper, pen.
(1) Put three kinds of objects on the floor, let the children irradiate them with flashlights, observe and record their shadows.
(2) Change the position of the flashlight to illuminate the small doll (opaque object), observe and record the shadow formed by the doll.
(3) The flashlight does not move, change the distance between the doll and the flashlight, and observe the change in the size of its shadow.
When light travels in a straight line, if it is blocked by an opaque object, it will form a shadow on the back of the object. Light can pass through transparent objects completely, so completely transparent objects cannot form shadows; when light passes through translucent objects, part of the light is transmitted, forming a translucent shadow. The shape and size of the shadow will be different depending on the angle of light irradiation. The size of the shadow varies depending on the distance of the object from the light source.
13. Little Hedgehog’s spines
Material preparation: magnets, iron filings, rectangular plastic tray, white paper of the same size as the bottom of the tray, and crayons.
(1) Draw a little hedgehog squatting under the apple tree on the paper, pay attention not to draw the thorns on the hedgehog.
(2) Spread the painting on the tray.
(3) Gently sprinkle the iron filings on the painting, then place the magnet under the tray, move the magnet gently, and suck all the iron filings onto the little hedgehog, helping the little hedgehog grow sharp spines.
Magnets can attract iron objects, and the finely broken form of iron filings can show a unique artistic shape under the attraction of magnets. The iron filings can also show the existence of the magnetic field of the magnets. By using the effect of the iron filings on the magnetic lines of force, young children can vividly perceive the distribution of the magnetic lines of magnets of different shapes.
14. Water absorption experiment
Material preparation: newspaper, electro-optical paper, paper towel, kraft paper, dropper, water basin, ruler, tape.
(1) Cut newspapers, electro-optical paper, paper towels, and kraft paper into strips of the same size, and then tape one end to the ruler so that the hanging strips are the same length. Place the ruler above the water surface by hand, let the strips of paper immerse in the water at the same time, and let the children observe which strip of paper rises faster, indicating that it has a strong ability to absorb water.
(2) Spread the four different papers on the table, and drop the same amount of water droplets on each piece of paper at the same time, and see which paper the water droplets spread the fastest.
There are many tiny holes in the plant fiber of paper, and the attraction of the fiber to water is greater than the attraction between water molecules, so that it can attract and retain water molecules under the action of gravity, which is called the water absorption of paper. Because the size and number of holes in the plant fibers of different papers are different, the strength of their water absorption is also different.
Material preparation: waste paper, water, glue, rubber gloves, plastic board, gauze, wooden sticks.
(1) Wet the waste paper and shred it, the smaller the better, and then soak it in an appropriate amount of water.
(2) Let the child wear rubber gloves to scratch the soaked paper, add glue and stir evenly with a wooden stick.
(3) Put the prepared pulp on the gauze net to dehydrate, and then spread it evenly on the plastic board and lay it flat to dry.
(4) Let the children feel the fun of making paper by themselves, and write and draw on the dried paper.
Paper is a sheet-like fiber product used for writing, printing, painting or packaging. Generally, it is formed by staggered combination of pulped plant fiber in water suspension on gauze, preliminarily dehydrated, and then compressed and dried. China is the first country in the world to invent paper.