​Molecules & Compounds

​What do aspirin, plastic wrap, and vinegar have in common? Give up? They are all compounds made from different combinations of the same three atoms: carbon, hydrogen, and oxygen. By themselves, these atoms cannot reduce pain, keep food fresh, or season food. But when they are chemically combined in certain ways to form compounds, they can be useful in many ways.

​Compounds and Chemical Bonds

​Most matter exists as compounds, not pure elements. That's because most pure elements are unstable. They quickly combine with other elements to make compounds. For example, water (H₂O) is a compound of hydrogen and oxygen.

What is a compound?

​Compound - a substance whose smallest particle includes more than one element chemically bonded together.

For example, water (H₂O) is a compound of hydrogen and oxygen atoms bonded together.

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​Atoms not particles.

Oh yeah! Remember how we've called everything particles before? Now we're going to refer to those tiny particles, as atoms!

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Atoms are the smallest functional unit of all matter.​

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What is a molecule?

​Molecule - a group of atoms held together by covalent bonds​

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​Compounds ARE molecules. The difference is that a compound is just a specific type of molecule, one that consists of MORE THAN ONE TYPE OF ELEMENT.

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All compounds are molecules, but not all molecules are compounds.

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Elements are molecules too, but they are made up of more than one of the SAME ATOM.

​PUT THIS DIAGRAM IN YOUR NOTES!!! USE COLORED PENCILS!

​Pure Substance

​This means that Compounds and Elements are Pure substances, but Mixtures are not.

​Even though compounds are made up of more than 1 type of atom, they are pure substances because the atoms are bonded together.

​Mixtures - contain more than 1 type of a substance, without a chemical bond between everything.​

​Virtually everything you interact with is a molecule. The oxygen you breathe is a molecule and a diatomic element (O₂), the food you eat is composed of sugar, fat and protein (all are large compounds), and the water you drink is a compound (H₂O).