Chemical Reactions The story

Hi there. This is H 2 O. So is this. Meet 2H 2 O

They weren’t always so happy.

Hmph. You’re out of control Bbbllgghh!!

You need me. I’m important. Meet O 2

He’s light. He’s fast. He’s crazy! Meet H 2 B-b-b-b-b

One day… Hey! Quit it!

One day…

Chemical Reactions Bonds are broken and new bonds are formed. Bonds in H 2 & O 2 break.

Chemical Reactions Bonds are broken and new bonds are formed. New bonds form.

Chemical Reactions New substances are formed. 2 gases react Water is formed

Parts of a Reaction Reactants: The chemicals you have before the reaction H2H2 That’d be us. Tbtbbhth! H2H2 O2O2

Parts of a Reaction Products: The substances created in the reaction H2OH2O H2OH2O

Chemical Equation ReactantsProducts Parts of a Reaction

Chemical Reactions During chemical reactions atoms are not created or destroyed. They’re just rearranged. 2 oxygen atoms 4 hydrogen atoms 2 oxygen atoms 4 hydrogen atoms

How can you tell if a chemical reaction has happened? Let me give you some hints.

Is it a chemical reaction? If a gas is produced it might be a chemical reaction. Look for the bubbles!

Is it a chemical reaction? If it changes color it might be a chemical reaction. Like iron rusting!

Is it a chemical reaction? If it gets hotter it might be a chemical reaction.

Is it a chemical reaction? Or…if it gets colder it might be a chemical reaction.

Exothermic Reactions Exothermic reactions release energy. These reactions feel hot.

Endothermic Reactions Endothermic reactions absorb energy. These reactions feel cold.