Introduction to Matter

Chemistry is the study of matter and how it changes...

Matter is anything that has mass and takes up space (or has volume).

There are 3 topics you have studied which are not matter because they have no mass or volume. What do you think they are?

Light

Sound

Electricity

AtomsAtoms

ElementsElements

CompoundsCompounds

MoleculesMolecules

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

compounds!!

ATOMS

The smallest particle that has properties of an element is an atom!

Atoms are matter!

What are the parts of an atom?????

ELEMENTSAn element is a substance that cannot be broken

down into a simpler substance.Each element has a one or two letter symbol.

RELATIVE AMOUNTS OF THE ELEMENTS IN YOUR BODY

COMPOUNDSA compound is a substance made of atoms of more

than one element bound together.

H2O2CO O2

MOLECULESMolecules are the smallest unit of a

substance that exhibit all of the properties characteristic of that substance.

H2OO2

CHEMICAL FORMULASA chemical formula is a written way to show what elements and how many atoms of an element are in a compound or molecule.

Example:

22starsor

I can count that I have four stars I have two to the second power in stars

H H H2

I can count that I have two atoms of Hydrogen (H)

orI can write the chemical formula by writing the symbol

for Hydrogen followed by a subscript that shows how many atoms of hydrogen there are

Practice!Two atoms of Oxygen:

O2

Four atoms of Carbon:

C4

One atom of Chlorine:

Cl

One atom of Carbon and two atoms of Oxygen:

CO2

If the chemical formula for a water molecule is H2O, what

does 3H2O mean???

Pure Substances v. Mixtures

A pure substance is matter with a fixed composition and definite properties. Compounds can be pure substances

A mixture is a combination of more than one pure substance.

Which of these are Pure Substances and which are Mixtures??

Cough Syrup Water

SugarApple Juice

Salt Water

Aluminum

Moving on...

MIXTURE!!!

PURE SUBSTANCE!!!

Classification of Mixtures

We can mix solids and liquids or liquids with liquids.

If the substances are not uniformly mixed; your substance is a heterogenous mixture.

If the substances are uniformly mixed then your substance is a homogeneous mixture.

Any part of a system that has uniform composition and properties is called a phase.

A homogeneous mixture will have one phase.

A heterogeneous mixture will have two or more phases.

When dealing with liquid-liquid mixtures...

A mixture with liquids that are miscible will dissolve into each other in various proportions.

A mixture with liquids that are immiscible will not mix with one another.