Making Sense of Matter Study Guide Matter is all around us… everything is made of matter.

Matter is anything that takes up space and has mass.

We can classify objects by their physical properties. Physical properties are ways we describe an object. Some of the ways we can describe and classify matter are by: Classify MATTER BASED ON PHYSICAL PROPERTIES Including, but not limited to:

1.mass – the amount of matter in an object (how many molecules make it up)­­measured in grams

2.magnetism – attracts metal (iron and steel) BUT NOT (aluminum, silver, gold, copper…)

3.physical state – solid, liquid, gas solid – tightly packed particles with little to no movement in a specific shape liquid – particles move some and will take the shape of any container gas – fast moving scattered particles

4. relative density (sinking and floating) 5. solubility in water – ability to dissolve

The solute is the substance dissolving; the solvent is what it is dissolved into Solids, liquids, and gases can all be dissolved into each other

6. the ability to conduct ∙ CONDUCTORS are metals – aluminum, copper, steel, iron, gold, silver or insulate ∙ INSULATORS are plastic, wood, Styrofoam, rubber

thermal (heat) or electric energy (will conduct electricity often with a plug or batteries – (a power Source))

What are tools we can use to classify matter?

tool picture what it measures

Beakers, Measuring cups, measuring spoons

Volume

Graduated cylinders

Volume

Thermometers

Temperature—boiling point, freezing point, melting point

Timing Devices­stopwatch

Time

Triple beam balances

Mass in grams

Digital scales

Mass in grams

Spring Scales

Force in Newtons (on Earth equals mass as well)

Rulers/measuring tapes

Length in meters, cm

Sense of sight

Size, shape, color, texture, patterns, parts of system, physical state

Sense of smell, hearing, taste

odor, sound, flavor

Sense of touch

Hardness, ability to roll, texture

Magnets

magnetism

beakers

Density, solubility, viscosity

Hand lens

Magnifies to see properties

Microscope

Magnifies to see properties

Computers, journals

Organization of data

We can classify matter in many different ways!!

Sometimes we need to use tools just to be able to see because matter can be really small. We use microscopes to magnify matter and give us the ability to see things we can’t normally see. When we look at a leaf with just our eyes, we see color, size, shape, texture. When we look at a leaf under a microscope, we can see the parts of the leaf that make photosynthesis happen!!!

We can use our eyes to describe This leaf’s color, shape, size, pattern of a young leaf.

We need a microscope to see the cells and chloroplasts on the tip

Matter changes physically if it is: Cut, torn, folded, frozen, melted, boiled, mixed,or if pieces are taken apart. Examples of physical changes: lemonade, folded paper, saltwater, melted ice, sharpening a pencil, or a mixture of paper clips and marbles.

Changing States of Matter

Sometimes matter changes its physical state. These changes occur because the matter has been heated or cooled. For example, water that reaches its freezing point turns into ice. Water that reaches its boiling point turns into water vapor. No matter what, it is still water. It has only changed state. The molecules that make up water are still the same. We call this a physical change. If it can return to the state it was previously, it has only changed physically.

LOSE ENERGY

As water loses heat energy, the molecules start moving slower. The are closer together.

If they lose enough heat energy, they will stop moving around each other and only vibrate against each other.

This is called freezing. Water freezes at 0˚C. It always freezes at 0˚C. One cup, one gallon, one droplet of water will ALWAYS freeze at 0˚C.

GAIN ENERGY

If water gains heat energy, the molecules start moving faster. They are spreading apart.

At 0˚C, they are no longer attached to each other and are able to move away/move around each other.

They are changing from solid state to liquid state. This is called melting. Water melts at 0˚C. It always melts at 0˚C. As water gains energy and the temperature rises, more molecules reach 0˚C and

melt.

As water continues to gain heat energy, the molecules continue to spread apart from each other and move faster.

At 100˚C they are moving very fast and spreading very far apart. The water molecules are turning from a liquid into a gas and are evaporating. This is called boiling. All pure water boils at 100˚C.

If you have 100 mL of water it will boil at 100˚C. If you have 300 mL, 1000mL, even 1567mL of water it will also boil at 100˚C.

**How can water melt and freeze at 0˚C???

It all depends on what is happening to the molecules­­if they are gaining energy they are melting; if they are losing energy they are freezing­­at the same temperature!

Density

Think: ball of cotton vs blob of rock… .They are the same size, but do they feel the same? No! They have very different masses. When you can compare an item’s mass to its volume you are finding its density.

Density describes how tightly packed the molecules of a substance are Density compares an object’s mass to its volume The more dense something is the more it sinks

Relative Density compares an object to water and describes the object’s buoyancy. If is is more buoyant it will float in water, if it is less buoyant it will sink.

Example 1 Styrofoam molecules are spread out Styrofoam’s mass is less than its volume which makes styrofoam

less dense than water. Objects that are less dense than water will float in water.

Example 2

A marble’s molecules are very tightly packed A marble’s mass is greater than its volume. It is more dense than water and will sink in water

Mixtures and Solutions Matter can be mixed with other matter. When two or more substances are combined we call it a mixture. Mixtures are usually easy to separate because each ingredient keeps its physical properties (for example, in a mixture of salad you can easily pick out the different vegetables). In some mixtures the ingredients spread out, and in others they can stay clumped together (based on their density). No matter what, the individual ingredients do not change. We can still see the individual physical properties. Anything we can separate with a simple tool or with our hands is a mixture. Some examples of mixtures are:

Cereal in milk, snack mix, ice water, and iron filings and sand. Sometimes one substance will dissolve into the other when mixing. This is a special mixture called a solution. You cannot see the individual solid particles anymore—but they are still there. In a solution, the molecules of one substance are dissolved evenly and are “uniformly distributed” (evenly spread around) into the molecules of another. Examples:

Water is an example of a solution of 2 hydrogen and 1 oxygen molecule. We cannot separate the hydrogen from the oxygen easily, and we cannot see their separate physical properties.

When a substance dissolves in water it does not “disappear”. It is still there. For example, when you dissolve salt in water, you cannot see it anymore but it is still there. The salt is now so small you cannot see it. Each water molecule has grabbed salt molecules in it. The salt has been evenly distributed throughout the water. You can evaporate the water and the salt will be left on the surface. In a solution, one item is the solvent and one is the solute.

The solute dissolves into the solvent. Lemon juice(solute) dissolves into water (solvent).

So many things will dissolve into water that we call water the “universal solvent”.

If something will not dissolve, we say it is insoluble. The temperature of the liquid will increase the speed in which things like sugar,

tea, or coffee will dissolve Solutions can be made of solids­liquids, but can also be made of liquids or gases that dissolve into other liquids or gases. Examples of solutions are: lemonade, air, carbon dioxide, brass, saltwater and Kool­Aid

How do we separate mixtures and solutions? Mixtures are easy to separate. We can use our hand or simple tools. We determine which tools to use based on the physical properties of the ingredients.

Separating Mixtures and Solutions

Type of Mixture Process to separate

Different sized solids (rocks + sand) ­Sieving using a strainer/sieve/colander ­If the pieces are large enough spoons, forks, tongs

Insoluble solids from liquids (sawdust + Filtering using filter paper

water)

Liquids that have different densities (oil + water)

Decanting­­allow one liquid to settle and one to float on top and then pour it off

Magnetic vs non­magnetic materials (steel + aluminum)

Magnetism­­the magnet will attract magnetic materials

Soluble solids from liquids (salt + water) Evaporation­­the water will evaporate and the salt will remain in the container

Density is a property that can be used to separate different liquids or solids and liquids—some things sink and others float! Another way to separate is by letting things settle into layers (think oil and water). Solutions are harder to separate but it IS POSSIBLE. The easiest way to separate a solution that has water in it is to evaporate the water.

For example, if you have a solution of salt water, once water reaches 100°C, it will evaporate and the only thing left in the dish will be salt crystals.Another example: If you added 20 ml of sugar to 100 ml of water, and then you evaporated the water, you will still have 20 ml of sugar in the dish.