Compounds

General Chemistry Index

Where are we going with this? The point of this deck is to give the background information and examples so that we can differentiate between substances (pure and mixtures) based on physical and chemical properties.

What are compounds?

Compounds are substances made up of two or more types of atoms that… hold that thought!

Good thing we defined atom on the elements page!

For instance, water is made up of hydrogen and oxygen. However, it is a single substance. You can't use a tool or a magnet to separate the hydrogen from the oxygen. This means that they are chemically combined. The combination of two or more atoms creates a thing called a molecule—if they do some hocus pocus and create a chemical bond.

It's not really hocus pocus, and all that bonding stuff is pretty much the heart and soul of chemistry. Maybe. Probably depends on who you ask.

So, a molecule of a substance results from the chemical bonding of two or more types of atoms in… hold that thought, too!

Back to water.  Water is made up of… hang on for this one… water molecules. Each water molecule has exactly 2 hydrogen atoms and 1 oxygen atom. 

You've heard of H20 probably. It's kinda famous.

Exactly two hydrogen and one oxygen combine to make one water molecule. Good to drink.

This is the fixed, specific ratio of hydrogen and oxygen that gives us water. Change the ratio, you (might) get a different type of molecule. So H202 is not water. It's hydrogen peroxide. Not good to drink.

Compounds are substances made up of two or more types of atoms that are chemically combined into molecules which are…

Molecules are formed when two or more types of atoms chemically combine in fixed, specific ratios.

So, saying it all at once, we get…

Compounds are substances made up of two or more types of atoms that… are chemically bound into molecules… in fixed, specific ratios

Saying the same thing different ways…

Compounds are substances made up of molecules.

Compounds are substances made up of two or more atoms that are chemically combined in fixed, specific ratios.

Compounds are substances made up of two or more types of atoms that are chemically combined into molecules.

In contrast…

Elements are made up of only one type of atom.

 

Mixtures are made up of two or more types of atoms or compounds that are NOT chemically combined.

 

https://youtu.be/oLKDD_T08dc