Imagine you and your friend just came back from a birthday party, each with a bag full of candy. Your friend makes you an exciting offer: you can take any one piece of candy from her bag, but there’s a catch—you can’t look inside! You really want a gummy frog, your favorite candy. Luckily, you have a secret trick up your sleeve: science!
When you reach into the bag, you can use the properties of the candy to find what you want. For a gummy frog, you would feel for something small, squishy, and frog-shaped. But this idea isn’t just for candy. We can use it to learn about other things too, like school supplies, breakfast cereals, or even hardware. How can we tell what an unknown substance is by its properties?
We know that a substance is made of one kind of atom or molecule and has specific properties. Some substances are elements, which means they can’t be broken down into other substances. We can group substances and elements by their properties. For example, metals are shiny, attracted to magnets, and good conductors of heat and electricity. They are often silver or gray in color.
Let’s think about gases. Gases don’t have a definite size or shape. Their molecules spread out to fill the container they’re in, and they are usually transparent, meaning light passes through them. Gases like carbon dioxide and oxygen share these properties. These specific properties help us identify unknown substances.
Imagine you have two unknown substances that look the same—whitish and powdery. How can you tell them apart? Remember, no tasting allowed! Instead, think back to what dissolves in water. If you try to dissolve a spoonful of each substance, the one that dissolves is sugar. Sugar dissolves in water, while sand does not.
Now, let’s level up. You have two mystery objects hidden from view. Your mission is to find out which one is metal. By touching them, you notice that object A is not flexible, while object B is squishy. This suggests that A might be metal. But in science, more evidence is better. So, you use a magnet. Object A is attracted to the magnet, while B is not. This confirms that A is metal—it’s a big old nail! And B? It’s your gummy frog!
Substances and elements have specific properties, like hardness, malleability, or magnetism. These properties help us identify unknown substances, whether it’s candy or hardware. And that’s the magic of science!
Property Hunt at Home: Go on a property hunt around your home! Find three different objects and describe their properties. Are they hard or soft? What color are they? Are they shiny or dull? Share your findings with a family member or friend and see if they can guess what the objects are based on your descriptions.
Gummy Frog Experiment: Create your own “mystery bag” with different types of candy or small toys. Without looking, use your sense of touch to identify each item based on its properties. Is it squishy like a gummy frog or hard like a piece of chocolate? After guessing, check to see if you were right!
Water Dissolving Test: With the help of an adult, try a simple experiment to explore how substances dissolve in water. Take two small cups of water and add a spoonful of sugar to one and a spoonful of sand to the other. Stir them and observe what happens. Which one dissolves? Talk about why this happens and how it helps us identify substances.
