Why Does a Soda Can Go Psst When You Open It?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why does a soda can go psst when you open it?

The Big Idea

A soda can goes psst because gas rushes out when you open the tab! Inside, the gas is squeezed at a higher pressure than the air outside. Opening the can lets it escape with a hiss.

Gas Inside

Step one: gas inside. A sealed soda can holds the drink and a gas called carbon dioxide at high pressure. The gas is squeezed in tightly, a bit like air in a pumped-up tire. That squeezing is called pressure.

The Tab Opens

Step two: the tab opens. When the tab opens, the gas rushes out through the small hole. That quick rush of air makes the hissing sound.

Pressure Evens Out

Step three: the pressure evens out. The pressure inside falls until it matches the air outside. Then the hiss stops, because there is nothing left pushing the gas out fast.

A Closer Look

Let's take a closer look! The can is sealed tight. Squeezed gas waits inside. When the tab opens, it hisses out. And bubbles of gas fizz up in the drink.

Quick Facts

Quick facts! The bubbles are carbon dioxide gas that was dissolved in the drink. Shaking a can makes many more bubbles, so it can spray. That is why you should never shake a can first. Always ask a grown-up to open cans and watch the sharp tab.

Think Like a Scientist

Now, take the challenge! With a grown-up, open a chilled can that has not been shaken. Listen for the hiss. Pour a bit into a glass and watch the bubbles rise. Why does the hiss stop after a moment?

Outro

A can hisses when squeezed gas rushes out and the pressure evens out. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!