Chapter One Chemical Building Blocks. Lesson One Introduction to Matter.

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Transcript of Chapter One Chemical Building Blocks. Lesson One Introduction to Matter.

Chapter One

Chemical Building Blocks

Lesson One

Introduction to Matter

Describing Matter

• Matter is the stuff that makes up everything in the universe.

• Some properties of matter include: hardness, texture, flammability, and color.

• Each specific substance has its own combination of properties that can be used to identify the substance.

Describing Matter

• Matter can change properties. Chemistry is the study of these properties and how matter changes.

• Matter can be classified as elements, compounds, or mixtures.

Describing Matter - Elements

• An element is a substance that cannot be broken down into any other substances by chemical or physical means. Ag = Gold.

• Elements are called the building blocks of matter because all matter is composed of elements.

• Each element is made up of tiny particles called atoms.

Describing Matter - Compounds

• A compound is a substance made of two or more elements combined in a specific ratio:

Al2O3 – Aluminum Oxide

Describing Matter - Formula

• A formula is a combination of symbols that shows the ratio of elements in a compound.

H2O

2 Hydrogen atoms + 1 Oxygen atom = one water molecule.

Describing Matter - Mixtures

• A mixture consists of two or more substances that are in the same place together but are not chemically combined into a new substance.

Examples: soil, sand, salt water, or orange juice.

The Earth

Solution

Describing Matter

• There are two basic ways that matter can change:– Physical Change: alters the form of a substance

but does not make the material into another substance. For instance, you break a pencil in half – it is still a pencil.

– Chemical Change: is a change is matter that produces a new substance – burning gasoline.

Physical Change

• Changing a piece of wood into a baseball bat – still wood.

Chemical Change

Chemical Change

MatterHas mass

Takes up spaceDEFINITION

MATTER

3 States:

Solid:-definite shape

-definite volume

Liquid:-indefinite shape-definite volume

Gas:-indefinite shape

-indefinite volume

Solid:-definite shape

-definite volume

Matter

The Newest State of Matter?

• Recently, scientists have added a fourth state of matter – which is now beginning to be introduced:

Plasma:-indefinite shape

-indefinite volume-electrically charged

particles

PLASMA

• Plasma’s definition is very similar to the definition of gas – no definite shape, no definite volume.– Plasma differs from gas because the particles

that make up plasma are electrically charged. The sun’s surface is one example of plasma – stars in the universe are also examples of matter in its plasma state.

Matter Changes

Lesson Two

Measuring Matter

Measuring Matter

• SI = Systeme International – The Metric System.

• The Metric System is based on powers of ten.

Table

Kilo 1000 k Kilogram (kg)

Hecto 100 h Hectoliter (hL)

Deca 10 da Decameter (dam)

--- 1 --- Meter (m), Gram (g), Liter (L)

Deci 0.1 d Decigram (dg)

Centi 0.01 c Centimeter (cm)

Milli 0.001 m Milliliter (mL)

Lesson Two – Measuring Matter

• Mass is a fundamental property of matter – all matter has mass. Mass is measured by how much stuff it contains.

• Mass and weight: mass and weight are not the same thing. Mass is the amount of matter in an object, while weight is the downward force exerted by an object due to gravity.

Measuring Matter

• Volume: The amount of space taken up by something – US system measures in gallons, quarts, pints, cups, and fluid ounces.– In the SI system, volume is measured in cubic

meters (cm3).

Volume

• The volume of rectangular objects, such as a block of wood can be found by multiplying: Length x Width x Height.

10cm3cm 4 cm

Length 10cm x Width 4cm x Height 3cm = 120cm3

Measuring Matter

• Density: if you have a one-pound brick and a sack of one-pound feathers, and you throw both out the window, which will land first?

Measuring Matter

• NEITHER: they both land at the same rate. – The amount of mass that a material has per unit of volume is

called density – how much matter is packed into a given amount of space.

– How does a ship float? The ship is made of heavy steel, however, the inside is space. The boat will float as long as its contents

weight less than the water the boat displaces. • If the boat fills with water – it sinks. (density increases – the

boat weights more than the water it can displace).

Density

• Density = Mass/Volume: A unit of density is always a unit of mass, such as grams, divided by a unit of volume, such as cubic centimeters = g/cm3.

Do not forget labels: Volume – cm3

Density – g/cm3

Lesson Three

Particles of Matter

John Dalton – Atomic Theory

1. Atoms cannot be broken into smaller pieces. Dalton imagined atoms to be like tiny marbles that were impossible to break.

2. In any element, all the atoms are exactly alike. This explains why an element always has the same properties.

3. Atoms of different elements are different.

4. Atoms of two or more elements can combine to form compounds.

5. Atoms of each elements have a unique mass.

6. The masses of the elements in a compound are always in a constant ratio. (All water molecules have 2 hydrogen atoms and 1 Oxygen atom).

How small are atoms?

• One grain of sand on a typical beach contains more atoms than there are grains of sand on the beach.

• There are 2,000,000,000,000,000,000,000 atoms of oxygen in one drop of water.

Atom Structure

Chemical Bonds

• Atoms can combine to form different compounds. The force that holds two atoms together is called a chemical bond.

• A combination of two or more atoms that are bonded together is a molecule.

H2O

O

H H

Water Molecule