Third Grade Science Experiments (Page 84)

Cardiovascular System Science: Investigating Heart Rate Recovery Time

STEM Activity

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As Valentine’s Day approaches, we’re increasingly confronted with stylized images of the heart. Real hearts serve very important functions – a person’s heart beats to supply blood to their entire body, and the heart has to work harder when they exercise. Have you ever wondered how quickly your heart beats when you exercise, or how long it takes to recover back to its normal rate after you’re done exercising? In this science activity, you’ll get to do some… Read more

Carnival Science: Summer of STEM (Week 1)

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Join Science Buddies this summer for virtual summer camp! Each week, we'll highlight fun STEM themes for kids of all ages, including suggestions for simple hands-on activities, book picks, and more. We'll keep you inspired all summer with creative and innovative science and engineering activities — for free. This week: big-top science with fun activities that tap into the spirit of the local fair, circus, or amusement park. Carnival… Read more

Cartography: Flattening the Earth

STEM Activity

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Have you ever let a map spur your imagination, wondering how life was as a world explorer sailing the oceans in search of new land? Maybe you see yourself drawing a map of your new discoveries. Wait a minute – you just realize Earth is round, so how do you create an accurate flat map? Throughout history, cartographers all around the world have found different methods for creating flat maps of Earth. None can represent reality exactly, but each is useful for specific purposes. Do this… Read more

Catch the Wave!

Science Fair Project Idea

Scientific Method

There is a lot of energy that can be harvested from moving water. Energy can be extracted from water rushing over a waterfall and from the regular patterns of the ocean's tides. The energy that propels waves forward in the oceans can also be extracted and used. But can wave energy power plants be built anywhere there is water? In this energy science fair project, you will use ocean buoy data and mathematics to determine which locations along the coasts of the United States can sustain a wave… Read more

Centripetal Force

Science Fair Project Idea

Scientific Method

What keeps you in your seat of a giant loop-de-loop roller coaster? Surprisingly, it is not the seatbelt but the seat! It works because of something called centripetal force and it does much more than make a great roller coaster. It keeps a satellite in orbit and you in your bicycle seat during a turn. How does it work? Read more

Changing Constellations

Science Fair Project Idea

Scientific Method

Do you like to look up into the night sky? There are so many stars, it can be mind boggling! Some ancient people marked time by the changes in star patterns. We still use changes in constellation patterns to mark astronomical time. Do constellations change more in one hour, one day, one month, or one year? Read more

Chemical Analysis of Rainwater

Science Fair Project Idea

Scientific Method

Here is an interesting project that could be approached from several different scientific angles: Environmental Science, Weather & Atmosphere, Chemistry, or Plant Biology. You can probably think of your own variations to emphasize the scientific area that most interests you. Read more

Chemistry of Baking Ingredients 1: How Much Baking Powder Do Quick Breads Need?

Science Fair Project Idea

Scientific Method

If you like to bake, this could be a good science project for you! Have you ever wondered about the purpose of each of the ingredients in your favorite recipes? For example, why is baking powder used in some muffin recipes? How does the baking powder affect how the muffins look, feel, and taste? In this food science project you will use a scientific method to find out! Read more

Chlorophyll Extraction

Science Fair Project Idea

Scientific Method

Chlorophyll is a natural pigment found in green plants. It is the primary pigment that absorbs light energy from the sun for photosynthesis. This energy is then used by the plant to synthesize glucose from carbon dioxide and water. Chlorophyll in the leaves of plants can be extracted and separated using chromatography. A good source of chlorophyll for an extraction is a dark green leafy vegetable like spinach. Rub a fresh spinach leaf on the bottom of a strip of filter paper. You can get a… Read more

Circular Reasoning: Finding Pi

STEM Activity

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Mathematicians look at the world around them in terms of numbers and formulas, and now, you can discover the formula for Pi too! In this science activity you will examine circular objects and see what you can discover about their sizes. As you explore, you might be surprised at how useful the results can be—maybe it will inspire you to save up for a bike with bigger wheels! Read more

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