5 Easy At Home Science Experiments w/ Mark Rober

Recent questions

• What is a vacuum in simple terms?

  A vacuum is a space devoid of matter. It occurs when air or other gases are removed from a container, creating a low-pressure environment. This concept is crucial in various scientific experiments, as it demonstrates how air pressure can influence physical phenomena. For instance, in the egg in a bottle experiment, the heat from a flame expands the air inside the bottle, and when the flame goes out, the air cools and contracts, creating a vacuum that pulls the egg into the bottle. Understanding vacuums helps explain many natural processes and is fundamental in fields like physics and engineering.

• How do you make homemade slime?

  Making homemade slime is a fun and simple process that requires just a few ingredients. Start with 1/2 cup of water and mix it with 1 teaspoon of borax to create a borax solution. In a separate bowl, combine old craft glue with an equal amount of water. Once mixed, gradually add the borax solution to the glue mixture, stirring continuously. You can customize your slime by adding food coloring if desired. The amount of borax can be adjusted to achieve your preferred slime consistency, and it's important to note that the bonding process can change over time, affecting the slime's texture.

• What causes surface tension in liquids?

  Surface tension in liquids is caused by the cohesive forces between liquid molecules. These forces create a "skin" on the surface of the liquid, making it behave like an elastic sheet. In experiments, such as the one using water, pepper, and dish soap, surface tension can be visibly disrupted. When dish soap is added to the water, it reduces the cohesive forces among the water molecules, causing the pepper to move away from the soap. This phenomenon illustrates how surface tension works and how it can be manipulated, providing insight into the properties of liquids and their interactions.

• Why do raisins float in carbonated water?

  Raisins float in carbonated water due to the presence of carbon dioxide bubbles that attach to their surface. When placed in the carbonated water, the bubbles cling to the rough surface of the raisins, providing enough buoyancy to lift them to the surface. As the bubbles rise, they eventually burst, causing the raisins to sink again. This cycle creates a visual effect similar to a lava lamp, demonstrating the principles of buoyancy and gas behavior in liquids. This experiment is a fun way to explore the interactions between gases and liquids, as well as the concept of density.

• What is elephant's toothpaste experiment?

  The elephant's toothpaste experiment is a popular demonstration of an exothermic chemical reaction that produces a large amount of foam. To perform this experiment, you need 6 oz of hydrogen peroxide, 1 tablespoon of dry yeast mixed with 3 tablespoons of warm water, and dish soap. When the yeast is added to the hydrogen peroxide, it acts as a catalyst, breaking down the hydrogen peroxide into water and oxygen gas. The dish soap captures the released oxygen, creating a foamy eruption that resembles toothpaste being squeezed from a tube. For a more dramatic effect, a higher concentration of hydrogen peroxide can be used, but safety precautions, such as wearing goggles and gloves, are essential due to the heat generated during the reaction.