Today I bring you a list with 10 scientific experiments for secondary That you can do with your students, or if you are a student you can propose them to your teacher.
Since ancient times, human beings have tried to explain natural phenomena by means of science. The gradual development of this has made it possible to understand and explain through experiments, generating information on how events occur in nature.
The information passes from one generation to another and that is reflected in educational programs. The goal is to help young people develop critical thinking skills and problem solving Which can be used throughout their lives.
Science is the only area in the academic world that not only transmits skills and facts, but also cultivates curiosity and creativity .
For this reason, science is an active process that can not be completely transmitted by passive teaching techniques, but has to be complemented with practical activities like experiments.
10 experiments for Secondary Education
1- The smell of an ester
Prepared in class, it can be identified by its characteristic odors. A ester Is an organic compound that produces different odors. Many fruits, vegetables and fatty animals contain esters.
Obtaining these is the combination of carboxylic acids and an alcohol, two organic compounds. The time required for this practice is 30 minutes and the materials to be used are:
- 5 test tubes.
- 50 g samples of benzoic acid and trans-cinnamic acid.
- 6 beakers of 100 ml of glacial acetic acid solution, bútric acid, formic acid and heptanoic acid.
- 6 beakers of 100 ml for methanol, ethanol , Isobutanol, butanol, pentanol and octanol.
- 16 test tubes.
- 2 microspheres.
- 1 ml plastic measuring pipettes for each solution.
- Sodium carbonate solution.
- 5% calcium bicarbonate solution in water.
- 18 Molar dropper (M) sulfuric acid (under a hood).
- For each group: hot plate, long beaker (400 ml to 600 ml).
- Distilled water.
- Four long test tubes.
- For each group:
- Single-hole test tube plugs
- Rack
- Four stirring rods
- Thermometer
- Test Tube Clamp
- Book of chemistry or access to Internet
- Glasses (one pair for each student)
- Hot Gloves
- Science Notebook
2- The chemistry of toothpaste
It has been present from ancient Egypt as a mixture of flowers, salt and spices. This concoction was rubbed on the teeth in a cloth.
With the development of science, toothpaste has been made with sodium bicarbonate And peroxide. The practice lasts 30 minutes. The materials to be used are:
- Five different brands or varieties of toothpaste.
- PH paper.
- Fluoride test strips.
- Distilled water (approx. 10 ml).
- Foil.
- Test tubes (approximately 5 per group).
- Parafilm Or stoppers for test tubes.
- 10 ml graduated cylinder.
- Spatulas.
- Cotton swabs (at least 5 per group).
- Scotch tape.
- Permanent marker.
- Science notebook.
3- Water Softeners
The qualities of water softened by 2 different techniques can be compared. Heavy water has magnesium and calcium ions, which interfere with the ability of the soap to work properly.
This type of water can clog and damage pipes, cause stains and buildup in sinks, tubs and sinks inside the house. Soft water contains only sodium ions that do not interfere with the ability of the soap to form foam.
In some cases, water can be softened by distillation, a process that requires boiling water, capturing the vapor, then condensing it and putting it back into a liquid. The time required for practice is 45 minutes. The materials to be used are:
- Distilled water (about 5 milliliters).
- Access to running water.
- Distilled water treated in 15 ml (1 tablespoon) salt Epsom Per 1 liter.
- Dishwashing liquid (other than detergent used in the dishwasher).
- Burning plate or Bunsen burner with ring holder, iron ring and wire.
- Gauze
- Protection glasses.
- Ring bracket with clamp.
- 2 250 ml beakers.
- 2 cups of 200 ml.
- Graduated cylinder.
- Thermometer.
- Flask of Florence.
- Condensation tube for distillation.
- 2 hoses for the distillation condenser, 1 m long.
- 2 hole plug.
- 1 hole plug.
- 3 test tubes with plugs.
- Paper parafilm.
- Plastic pipettes.
- Half cup calcium hydroxide .
- Half a cup of calcium bicarbonate.
- Ion exchange resin beads, approximately 100 ml.
- Large plastic funnel.
- Electronic balance.
- Filter bottle with vacuum hose.
- Vacuum pump.
- Filter paper.
- Internet access or a Chemistry textbook.
- Science notebook.
4- Lewis structure
Lewis structures can be used to predict the binding capacity of molecules.
An atom has a small but dense nucleus that is composed of protons (positive) and neutrons. The nucleus is surrounded by charge of electrons (negatives) that have paths known as orbits.
Atoms are stable when their outermost orbits are filled with electrons. The experiment consists in placing the sweets between the molecules as a representation of the atoms that unite them. The duration of the practice is 30 minutes. The materials to be used are:
- Plastic cups containing about 30 small colored candies.
- The periodic table.
- Cards, about 40.
- Science notebook.
5- Show the breath of a plant
The plant is placed in a test tube held in a block of wood. Place in a bowl containing lime water and cover the plant with 1 jar. Keep the plant in a dark place for several hours or examine the next day.
The lime water will be milky, showing that CO 2 Expelled and the increase in level show a considerable amount of oxygen that was taken.
6- Test the gas emitted when the seeds germinate
Put some mustard seeds in a jar with a little damp cotton. In the apparatus shown in image # 1, they are allowed to germinate for a few days. The cork is carefully removed and the water is poured through the thistle funnel.
Open the clip and allow the displaced air to bubble through the lime water. This becomes cloudy, showing the presence of carbon dioxide.
7- Mounting Boxes for Insect Collections
Boxes of wood or cardboard cigars serve as useful and convenient covers for insect collections. After the insect has been removed from the stretching board a pin is placed through the body and then sticks to the bottom of the box to hold the insect.
The pins are arranged in an orderly manner and may carry, near the upper end of the pin, a small card on which the data on the insect are filled.
Cigar boxes can also be used to mount insects on the cotton bottom. The cover is removed and the inside of the box is filled with layers of cotton lint.
Subsequently the insects are arranged on the lint and covered with glass or cellophane, which is recorded to the box making a permanent assembly.
This type of mounting box is especially suitable for butterflies and moths or for exhibitions in a school museum.
8- A worm farm
A 30 cm by 30 cm by 15 cm wooden box is required, equipped with a glass front that is useful for studying earthworm habits.
The box is filled almost to the top with layers of (a) sand; (B) leaf mold and (c) loam, filling each layer before adding the next one (see image n ° 2).
Lettuce leaves, dead leaves, carrots, etc. are placed. On the surface soil, along with some worms. The moist content is maintained and the behavior of the worms is studied.
9- Provision of grasshoppers and climbing insects
Grasshoppers and climbing insects are provided. These insects can be kept in an inverted jam jar, as shown in figure 3. They should be provided with a bit of foliage, which can be placed in a jar of potted meat.
To give more space to the insect and save it from drowning, the jar can rest in an inverted shoebox with the leaves projecting what is now the top. The holes should be drilled in the shoe box to ensure sufficient fresh air supply.
10- The effect of rain on the sloping ground
Fill a pan or shallow box with firmly packed soil. It is placed in the rain with one end raised slightly.
You can see how raindrops sprinkle the soil towards the low end. This experiment can be done indoors using a shower to simulate the rain.
The Importance of Experiments in Education
The question for educators has always been"what is the best way to teach science?". There are no simple answers to this question, but education studies provide interesting approaches.
Research indicates that students need to be actively involved in science, to learn through experience.
They are encouraged to go beyond the textbook and ask questions, consider new ideas, formulate their own predictions, develop experiments or procedures, gather information, record results, analyze recommendations, and use a variety of resources.
Students can not only listen to science, they must also do it. To do science is about performing experiments.
In the science curriculum, experiments play a number of educational roles. In some cases, manual activities serve as a hook to engage students and introduce new topics.
A discrepant event used as an introduction to experiments engages questions and inspires students to seek the answers behind the recommendations.
Classroom research can also help expand the information that was previously introduced or set new knowledge.
To impart science knowledge to young people, it is necessary to carry out experimental practices in non-formal science education, with game strategies.
With these experiments corrections of concepts emitted in the mass media can be made. In this way you can achieve positive results in teaching and learning science.
The most popular experiments developed in laboratory practices of the basic sciences as biology , Physical Y Chemistry Allow the learner to have the opportunity to put into practice the theory learned prior to the session.
References
- Gómez, A. (2004). Fun Chemistry Experiments for Young People . Medellín, University of Antioquia.
- Walker P. (2011). Petronet: Chemistry Experiments. Retrieved from: petronet.ir.
- 700 Science Experiments for Everyone compiled by UNESCO. New York, Doubleday.
- Materials Science and technology. Retrieved from: pnl.gov.
- Shi, J. University of California: High School Science Fair Projects. Retrieved from: cert.ucr.edu.