States of Matter

What is matter made of?

Matter is made of atoms and molecules (your book refers to these as particles)

Atoms

Atoms are the smallest particles of elements.› They are made of protons, neutrons, and

electrons Atoms can combine to form compounds

or molecules. Compounds are two or more elements

chemically combined in a specific ratio (i.e. H2O 2 hydrogens to 1 oxygen [2:1 ratio])

Molecules

Molecules are made up of atoms combined in specific ratios › i.e. Hydrogen gas: H2

Every combination of atoms is a molecule. › In this example, two hydrogen atoms make a

molecule of hydrogen gas.

BUT…. not all molecules are compounds

› Since Hydrogen gas only contains the element Hydrogen, it’s not a compound

In conclusion, all compounds are molecules but not all molecules are compounds

Solids

A state of matter that has a definite shape and volume.

The particles are very close together and have strong intramolecular attractions that hold them together

The particles move, but not fast enough to overcome the molecular attractions (bonds)› Basically the particles vibrate in place

Liquids

State of matter that has a definite volume but no shape (it takes the shape of its container)

The particles move fast enough to overcome some of the molecular attractions so they can slide past each other

Properties of Liquids

Surface tension- think of it like an elastic “skin” of a liquid

property of the surface of a liquid that allows it to resist an external force (i.e. a water strider bug)

Has to do with cohesion (attraction) of molecules to each other more than to the air above the liquid.

https://www.youtube.com/watch?v=aVmU3CLxvgU

Properties of Liquids

Viscosity- a liquid’s resistance to flow. › The stronger the attraction between the molecules of a liquid, the more viscous it is (harder to flow)

› Example: honey, syrup, molasses, etc….

Gases

State of matter that has no definite shape or volume.

Particles move so quickly they can overcome the molecular attractions and break away from one another

Plasma

An ionized gas› This means that so much heat (energy)

has been added to the molecule that the electrons break free and exist separately from ions (positively charged particles)

› Examples of plasma: the sun, the Northern Lights (auroras), lightning , fluorescent lamps and neon signs

› https://www.youtube.com/watch?v=3T49f2TFuiM

What happens when we change the temperate of a solid, liquid, or gas?

Lab Results

When we heat a substance, what happens to its molecules…

Phase Change Vocab

Temperature- the average motion of molecules/ a measure of how fast the particles are moving› Measuring the kinetic energy

Phase Changes