How are Elements, Compounds and Mixtures Similar? Different?

Note that an element: consists of only one kind of atom cannot be broken down into a simpler type of matter by either physical or chemical means can exist as either atoms or molecules

A molecule consists of two or more atoms of the same element. Did you know? A molecule consists of two or more atoms of the same element.

How do elements bond together? You must first learn why atoms bond together. We use a concept called "Happy Atoms." We figure most atoms want to be happy, just like you. The idea behind Happy Atoms is that atomic shells like to be full. That's it. If you are an atom and you have a shell, you want your shell to be full. Some atoms have too many electrons (one or two extra). These atoms like to give up their electrons. Some atoms are really close to having a full shell. Those atoms go around looking for other atoms who want to give up an electron.

For example, oxygen atoms have 6 electrons in their 2nd electron field, leaving 2 slots open. One oxygen atom will bond with 2 hydrogen atoms to create water. Now, the oxygen’s outer electron field is full making it stable and HAPPY! 

Note that a compound: consists of atoms of two or more different elements bound together, can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means), has properties that are different from its component elements, and always contains the same ratio of its component atoms.

Which ones are examples of compounds? Molecules?

Common Compounds Table Salt Water Carbon Dioxide Sugar Baking Soda Sodium and chlorine Water Hydrogen and oxygen Carbon Dioxide Carbon and oxygen Sugar Carbon, hydrogen, and oxygen Baking Soda Sodium, hydrogen, carbon, and oxygen

Note that a mixture: consists of two or more substances not chemically combined can be separated into its components by physical means often retains many of the properties of its components

Look at a sedimentary rock. It is a mixture Look at a sedimentary rock. It is a mixture. See how you can see the different pieces in the granite.

Can you think of anything else that is a mixture?

Mixtures come in different shapes and sizes Mixtures come in different shapes and sizes. Sometimes they don’t even look like mixtures. One type of mixture that can fool the eye is called a solution. An example of a solution is Kool-Aid. Solution: mixture that appears to be a single substance but is composed of particles of two or more substances that are evenly distributed.

There are 2 parts to a solution: Solute: substance that is dissolved Solvent: substance in which the solute is dissolved

Which one is the solute? Solvent?

Concentration: measure of the amount of solute dissolved in a solvent Look at the picture of the marbles. What color has the highest concentration? Look at the

More Mixtures… Suspension: mixture in which particles of a material are dispersed throughout a liquid or gas but are large enough to settle out.

More Mixtures… Colloid: mixture in which the particles are dispersed throughout but are not heavy enough to settle out.