Fourth Grade Science Experiments (Page 139)

Bacteria Can Fix It! A Comparison of Nitrogen-Fixing Bacteria and Nitrogen Fertilizers

Science Fair Project Idea

Scientific Method

Do you know what plants need to grow? Sure, they need soil, water, and sunshine. Everyone knows that. But here's a secret: they also need nitrogen. Plants use nitrogen to make DNA in their cells and the proteins that lead to healthy stems and leaves. The problem is, although the Earth's atmosphere is made up of 78% nitrogen, the form of nitrogen found in the atmosphere cannot be used by plants. So how do plants get their nitrogen? Either through nitrogen deposits in the soil, or through… Read more

Bacterial Resistant Materials and the Best Disinfectant

Science Fair Project Idea

Scientific Method

If you'd rate yourself high on the bacteriophobia scale, just keep on scrolling down to the next project. Bacteria are all around us, and normally our body's defenses keep us blissfully unaware of them. If you don't mind finding out where they're lurking in your house, then you might find this project interesting. Read more

Balancing Challenges

STEM Activity

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9 reviews

Did you ever come across a challenge that looked almost too straightforward to try, but turned out to be shockingly tricky, if not impossible? This activity challenges you in a fun way. Something as simple as picking up a piece of candy can be way harder than it looks. Find out why some movements are harder than you’d expect, then trick your friends into trying them. Astonish them with your stunning knowledge of the laws of physics; and most of all, have fun! Read more

Ball Dribbling Science: Weekly Science Project Idea and Home Science Activity Spotlight

Blog Post

In this week's spotlight: a sports science that looks at the physics of what is going on when you dribble a basketball. After you push the ball to the floor, the ball meets the floor or court and then returns, but it doesn't necessarily return to the same height. What does the surface of the floor have to do with how a ball bounces when dribbled, how much effort a player has to use to keep the ball dribbling uniformly, and what is going on with the energy of the ball in motion? Put it to… Read more

Balloon Powered Sound! Build Your Own Balloon Amplifier

STEM Activity

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Have you ever watched an old movie, or a cartoon, where a character holds a cone to their ear in order to hear what people are saying? Believe it or not, those cones (known as ear trumpets) were the very first hearing aids and were very popular for a time. Even Ludwig Van Beethoven used one! They helped people hear by acting as a sound amplifier, collecting sound waves and focusing their energy into the ear. In today’s activity you are going to make a different type of sound amplifier… Read more

Be Seen After Dark—What Clothes Keep You Safe?

Science Fair Project Idea

Scientific Method

Did you know that the most likely time to be struck and killed by a car in the United States is at dusk, dawn, or at night? In 2014, 3 out of every 4 pedestrian fatalities happened in these types of poor light conditions. Is there something you could do to decrease the chances you, your friends, and your family members are safer when walking or biking at night? Do you think the types of clothes that you wear could make a difference in how visible you are to drivers? Explore the science of… Read more

Bend or Break? Candy Science

Blog Post

What happens when you bend your favorite candy in half? Does it break? Does it bend? Does it snap back into shape? In this week's materials science-themed family science activity, students put candy to a "bend it" test to explore how some materials are more flexible than others. While it may be obvious that some candy bars will break (or snap in half) when bent while other more "gummy" candies bend, changing the temperature of the candies gives this experiment an extra… Read more

Best Wand for Big Bubbles

STEM Activity

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Have you ever tried to blow a bubble, and no matter how hard you try, the bubble just will not form? Why does this happen? Why do bubbles form at all, and why is it harder to blow bubbles sometimes? In this activity, we will explore the limits of how big our bubbles can get! Read more

Biodiversity Survey

Science Fair Project Idea

Scientific Method

Survey your area to find out which species of plants and animals live there. You might be surprised to find out that something you grew up thinking was very common, is actually quite unique! For example, if you live in the great plains, then you may think that prairie dogs are a nuisance or a pest. Actually, some species of prairie dogs are only found here, and have a very important role for short and tall grass prairie ecosystems. The prairie dogs are an important part of the food-chain, and… Read more

Bits, Bytes, and Bases: Write a JavaScript Binary/Decimal/Hexadecimal Converter

Science Fair Project Idea

Scientific Method

This is a challenging first computer science project. You'll learn the basics of how digital devices can represent numbers using only 0's and 1's, and you'll write a JavaScript program to convert numbers between binary, decimal and hexadecimal notation. Read more

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