Atoms, Elements, Molecules, & Compounds

ATOM COMPOSITION

•Atoms are extremely small.

•One teaspoon of water has about as many

atoms as the Atlantic Ocean has drops of

water.

The atom is mostly

empty space!

An atom consists of a

• nucleus in the center

–(it contains protons and neutrons)

• Electrons circle around in space about the nucleus.

The Atom

Nucleus

Electron cloud

An atom is the smallest particle of matter.

Draw the atom and label the model below.

Nucleus

Electron cloud

The Language of ChemistryELEMENTS

An element is a pure substance that cannot be broken down into other substances. An element is made of only one type of atom.

SodiumBromine

Aluminum

Elements

Elements are a lot like the letters of our alphabet. Just as the 26

letters make up all the words we know, the elements make up all

the matter in the universe.

The 118 known elements make up all the matter we know of in our

universe!

Compounds

A compound is a substance formed when two or more

elements are chemically joined

creating a completely unique substance.

Some examples of compounds are salt

(NaCl) and Water (H²0)

Compounds

– Compounds contain two or more elements in a fixed ratio-like a recipe!

– Compounds have properties different from those of the original separated elements

– EX: table salt (NaCl)

– Sodium and Chlorine

The compound sugar can be broken down into :

Carbon CHydrogen HOxygen O

A chemical change can separate (or combine) elements to create the different substances.

Because CHEMICAL COMPOUNDS are made

up of different types of atoms they can be broken down or separated to those individual atoms. Remember the sugar???

SUGAR

C6H12O6

A MOLECULE is the smallest unit of a compound

that still retains the chemical characteristics of the compound.

MULA

H2O – DRAW THIS C8H10N4O2 - caffeine

Elements/Atoms/MoleculesBecause elements are substances that CANNOT be broken down into simpler substances – a molecule of

an element is usually the same as an atom of that element.

If you continually cut up a piece of aluminum you will reach a point where you can no longer divide it into smaller units. You have one atom of aluminum. An atom of the element aluminum is also a molecule of

aluminum.

But a molecule of sugar (a compound ) is made up of a combination of the three types of atoms: carbon,

hydrogen, and oxygen. If you keep continually break down sugar you will eventually not have sugar but the

three elements which make up sugar!