Topic - Science Experiments
By Loralee Leavitt, Candy Experiments
At the USA Science and Engineering Festival in Washington, DC, children crowd around the Candy Experiments booth. A volunteer asks if they’re ready to take the marshmallow challenge: “Can you sink a marshmallow?”
As Steve Spangler teaches in the lemon and lime sink-and-float experiment, an object sinks if it is more dense than water. It floats if it is less dense than water.
When you drop a marshmallow in water, it floats like a balloon. A marshmallow is full of air bubbles, which puff it out. The sugar in the marshmallow gets spread out over a large area, making the marshmallow less dense than water. So how do you make a marshmallow denser? You have to make it smaller.
To try the marshmallow challenge, take a mini marshmallow and squash it. You can do this by smashing it between your palms, rolling it between your fingers, or smashing it against a flat surface. Try to roll it into a ball rather than flatten it into a pancake, because a pancake shape floats better than
Reveal invisible secret messages and drawings under a black light with a spooky homemade Halloween projector.
These handheld projectors are perfect for puppet shows, lighting up while trick or treating, flashing messages in the dark to your friends, haunted houses and more. Take them outside for fun after dark. Decorate a piece of paper, draw your message or picture with a fluorescent highlighter, glue it to a cup, add a black light and you are ready to take on the night.
With the Black Light Secret Message experiment, you’ll see that certain highlighters aren’t just brightly-colored – they’re actually fluorescent and glow underneath a black light! The secret messages and floating images you’ll create with this experiment are sure to create screams of joy and shrieks of excitement. Some even break open highlighters and squeeze out the ink to make glowing potions. On Friday, we will share the Science Behind some of our favorite glowing recipes.
We recently came across this video by SooToday.com‘s reader Phil Sabine making its rounds on the Internet. In the video, Sabine takes a cold bottle of water, turns it upside down and then taps the bottom. The water instantly begins freezing from the bottom down to the top.
Is it magic? A slight of hand? Or did he switch the liquid in the bottle to something other than water?
The answer to all of the questions is no, there is no trick. The solution lies in the science behind the freezing temperature of water and how ice crystals form. This is also referred to as Supercooled Water.
Everyone knows the freezing temperature of water is 32 degrees Fahrenheit or 0 degrees Celsius. When this temperature is reached, the water molecules freeze by forming ice crystals. It’s easier for the water molecules to turn to ice on top of already formed crystals. Ice crystals build on existing ice crystals to eventually freeze the entire bottle of water.
What starts the freezing ice crystal process?
The process of starting the ice crystals is called “nucleation.” This starts from an impurity or scratch or piece of dust on the container holding the water. In this case, the
Becky Ditchfield never wants to know what we’re doing for our Science Mondays segment on KUSA-TV 9News. This was our last segment of the year and I wanted to make it one for her to remember. I pulled out an old favorite from the Spangler repertoire, but it was new to Becky. In anticipation of your next question, here’s the disappearing ink recipe.
We salute and thank all of those great teachers out there who find engaging activities to get their students back in the seats and ready to learn for another school year. If you’re a teacher, you know all too well the challenges we face keeping our students engaged and interested. If we’re not careful, it’s easy for some students to disappear into their surroundings and become that “invisible kid.” This segment featured two demonstrations from our Science of Leadership workshop for teachers that use elements of the science demonstration as a metaphor for learning. Oh, by the way, teachers shared their best first days of school activities on our Facebook Fan page this week.
Take a look at our First Days of School Kit with ideas for getting your students excited about the year after the first bell.