10 At-Home Science Fair Ideas for Primary School
Explore 10 safe, at-home Brazilian science fair project ideas for Class 1-5 with materials, safety lines, and core scientific principles.
- Items
- 10 to play
- Takes
- about 7 min
- Scoring
- 1 point a right answer, +1 without the hint
- Clock
- 30 seconds an item
Bom dia, turma! Welcome to our Feira de Ciências at-home challenge, where you guess the scientific principle behind ten fun experiments you can try for our school science fair!
Project
Hint:
The science
Muito obrigado, todos! Talk to your science teacher and start planning your home project safely today!
All 10, with the answers
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1easy
Project: Vulcão de Bicarbonato e Vinagre Vulcão de Bicarbonato e Vinagre
Hint: You will need baking soda, vinegar, dish soap, and a plastic bottle.
The science: Mixing an acid and a base creates carbon dioxide gas that bubbles up rapidly. This causes a foamy eruption out of the bottle neck.
Acetic acid in vinegar reacts with sodium bicarbonate to form carbon dioxide gas.
🛟 Perform this experiment on a tray in a well-ventilated space under adult supervision.
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2easy
Project: Lâmpada de Lava Caseira Lâmpada de Lava Caseira
Hint: You will need water, cooking oil, food coloring, and an effervescent tablet.
The science: Oil floats on water because it is less dense, and effervescent tablets create gas bubbles that carry colored water to the top.
Immiscible liquids separate by density, while carbon dioxide carries liquid droplets upward.
🛟 Keep the tablet away from young children and do not seal the container tightly.
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3medium
Project: Arco-Íris no Copo de Açúcar Arco-Íris no Copo de Açúcar
Hint: You will need water, sugar, food coloring, a spoon, and clear glasses.
The science: Adding different amounts of sugar creates liquids with different densities that stack without mixing.
Higher sugar concentration increases solution density, allowing lighter layers to sit on top.
🛟 Clean up any sugary spills immediately to keep your workspace dry and safe.
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4easy
Project: Ovo Flutuante na Água Salgada Ovo Flutuante na Água Salgada
Hint: You will need two fresh eggs, water, table salt, and two tall glasses.
The science: Salt water is denser than fresh water, providing enough buoyant force to hold the egg up.
Dissolving salt increases water density, exceeding the overall density of the raw egg.
🛟 Handle raw eggs carefully and wash your hands thoroughly with soap after handling.
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5easy
Project: Pimenta em Fuga com Sabão Pimenta em Fuga com Sabão
Hint: You will need a shallow bowl, water, ground black pepper, and dish soap.
The science: Dish soap breaks the surface tension of water, causing pepper flakes to rush to the sides.
Soap acts as a surfactant, weakening hydrogen bonds at the water surface instantly.
🛟 Avoid touching your eyes after handling ground pepper.
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6medium
Project: Telefone de Copo de Plástico Telefone de Copo de Plástico
Hint: You will need two plastic cups, a long piece of string, and a paperclip.
The science: Sound vibrations travel along the taut string much faster than through open air.
Mechanical sound waves transmit efficiently through solid longitudinal vibration.
🛟 Have an adult help punch the tiny hole in the bottom of each plastic cup.
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7medium
Project: Leite Mágico Colorido Leite Mágico Colorido
Hint: You will need whole milk, food coloring, a cotton swab, and dish soap.
The science: Soap molecules attach to fat droplets in the milk, creating swirling currents of food coloring.
Surfactants alter surface tension while disrupting fat molecules dispersed in the milk.
🛟 Do not drink the milk or soap mixture after completing the experiment.
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8medium
Project: Carrinho Movedor a Balão Carrinho Movedor a Balão
Hint: You will need a plastic bottle, straw, balloon, tape, and bottle caps for wheels.
The science: Escaping air drives the lightweight car forward in the opposite direction.
Newton's third law states that every action force produces an equal and opposite reaction force.
🛟 Wear safety glasses when cutting plastic bottles and blowing up balloons.
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9hard
Project: Bússola Caseira com Agulha Bússola Caseira com Agulha
Hint: You will need a sewing needle, a magnet, a cork slice, and a bowl of water.
The science: The magnetized needle aligns itself with Earth's magnetic field lines while floating freely.
Ferromagnetic metals align their magnetic domains along natural geomagnetic orientation.
🛟 Carefully insert the sewing needle into the cork under adult supervision.
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10hard
Project: Filtro de Água de Garrafa PET Filtro de Água de Garrafa PET
Hint: You will need a cut PET bottle, cotton, sand, gravel, and activated charcoal.
The science: Layers of gravel, sand, and charcoal trap debris and suspended particles physically.
Physical filtration traps large sediment while porous charcoal absorbs impurities.
🛟 This demonstration filters visible dirt only, so do not drink the filtered water.
So the hall plays along
Worth knowing
- Science fairs in Brazil are called Feiras de Ciências and encourage hands-on discovery.
- Projects follow the scientific method by asking questions, testing hypotheses, and observing outcomes.
- Primary school experiments (Class 1-5) focus on observable physical and chemical changes.
- All at-home experiments require adult supervision and clear safety rules.
- Materials should use simple household items like vinegar, baking soda, water, and food coloring.
Where it is played, and why
Preparing for your school Feira de Ciências is an exciting way to discover how the world works. This game lets you host a hall or classroom activity where classmates guess the scientific principles behind ten simple home experiments. Read each project title, offer a hint if needed, and count down before revealing the answer. Every project uses everyday household items and includes a key safety rule so you can learn safely.
About this piece
- Science fairs in Brazil, known as Feiras de Ciências, emerged between the 1950s and 1970s in São Paulo.
- The main goal of a science fair is to promote practical learning, curiosity, and teamwork.
- Projects follow the scientific method by asking questions, testing hypotheses, and analyzing results.
- All home science activities require adult supervision and a clean, well-ventilated workspace.
- Safety measures include wearing closed shoes, tying long hair back, and wiping spills immediately.
How it is done
- Brazil: Science fairs emphasize practical and experimental learning where students solve everyday problems under teacher and parent guidance.
- United States: School science fairs date back to 1921, promoting simplified scientific principles and practical testing.
- Canada: Educational centers provide home laboratory guidelines to ensure safe hands-on experiments for students.