Chapter 11 Lecture Conceptual Integrated Science Second Edition © 2013 Pearson Education, Inc. Investigating Matter

Chapter 11 Lecture

ConceptualIntegrated Science

Second Edition

© 2013 Pearson Education, Inc.

Investigating Matter


This lecture will help you understand:

• Chemistry: The Central Science• The Submicroscopic World• The Phases of Matter• Physical and Chemical Properties• Determining Physical and Chemical Changes• Elements to Compounds• Naming Compounds


Chemistry: The Central Science

• Chemistry is the study of matter and the transformations it can undergo.







• Chemistry is the "central" science.


Physics Biology

AstronomyEarth Science


Chemistry



• Chemistry is a "materials" science.– Most of the material items in any modern

house are shaped by some human-devised chemical process.





• More than 70% of all legislation placed before the U.S. Congress addresses science-related questions and issues.


Chemistry: The Central ScienceA situation to ponder…

• Collagen cross-link inhibitors that significantly reverse various aspects of aging have recently been discovered.


Chemistry: The Central ScienceCHECK YOUR NEIGHBOR

Collagen cross-link inhibitors that are clinically tested to be safe and effective should be

A. available to the general public.B. available only to those 21 and older.C. available only by prescription.D. prohibited because of their abuse potential.E. prohibited because growing old should be

natural.

Explain your answer to your neighbor.


Chemistry: The Central ScienceCHECK YOUR ANSWER

Collagen cross-link inhibitors that are clinically tested to be safe and effective should be

A. available to the general public.B. available only to those 21 and older.C. available only by prescription.D. prohibited because of their abuse potential.E. prohibited because growing old should be

natural.


The Submicroscopic World

• A single grain of sand contains about 125 million trillion atoms.

• How much is 125 million trillion??



• Roughly 250,000 dunes of this size contain about 125 million trillion grains of sand.

• Yet, that's how many atoms there are in a single grain of sand. (Atoms are small.)


Chemistry: The Submicroscopic WorldA situation to ponder…

• Are atoms made of molecules, or are molecules made of atoms?




The Phases of Matter

• One of the most evident ways we can describe matter is by its physical form, which may be one of three phases (also sometimes described as physical states):


• The gaseous phase of any material occupies significantly more volume than either its solid or liquid phase.

• Frozen carbon dioxide, CO2, "dry ice"



GasGas

LiquidLiquidSolidSolid

DepositionDepositionSublimationSublimation

MeltingMelting

FreezingFreezing

CondensationCondensationEvaporationEvaporation



Physical and Chemical Properties

• A physical property describes the look or feel of a substance.



• A chemical property describes the tendency of a substance to transform into a new substance.


It is a chemical property of iron to transform into rust.




• A physical change is a change in the physical properties of a substance.




• Chemical properties are properties that characterize the ability of a substance to react with other substances or to transform from one substance into another.



• Any change in a substance that involves a rearrangement of the way atoms are bonded is called a chemical change.

Determining Physical and Chemical Changes


CarbondioxideCarbondioxideOxygenOxygen CarbonCarbon




• A physical change is a change in the physical properties of a substance.

• A chemical change is the transformation of one or more substances into others.– A substance is identified not only by the kinds

of atoms it contains but also by how those atoms are connected to one another.

– During a chemical change, a new substance is formed as atoms rearrange themselves into new configurations.


O=O

O=O

O=O

OO

O O

O

O

Oxygen Ozone

Determining Physical and Chemical Changes CHECK YOUR NEIGHBOR The transformation of oxygen, O2, into ozone, O3, is an example of

A. a physical change.B. a chemical change.C. both a physical and a chemical change.D. neither a physical nor a chemical change.



O=O

O=O

O=O

OO

O O

O

O

Oxygen Ozone

Determining Physical and Chemical Changes CHECK YOUR ANSWERThe transformation of oxygen, O2, into ozone, O3, is an example of

A. a physical change.B. a chemical change.C. both a physical and a chemical change.D. neither a physical nor a chemical change.

Explanation:The same kinds of atoms are involved, but how they are arranged is completely different. Thus, a new substance has been formed.



• A physical change imposes a new set of conditions on the same material.

• A chemical change forms a new material that has its own unique set of physical properties.

• Both physical and chemical changes result in a change in physical appearance.


Potassiumchromate

Potassium chromate + Heat Potassiumchromate(cooled)


• Physical or chemical change?


Physical or chemical change?

Ammoniumdichromate

Ammonium dichromate + Heat Ammonia,water,chromium(III) oxide



• Is growing up a physical or chemical change?• Hint: Does this boy look like the peanut butter

sandwich he ate in order to grow?


Determining Physical and Chemical Changes CHECK YOUR NEIGHBOR

Melting a piece of solid gold is

A. a physical change.

B. a chemical change.

C. both a physical and a chemical change.

D. neither a physical nor a chemical change.



Determining Physical and Chemical Changes CHECK YOUR ANSWER

Melting a piece of solid gold is





Explanation:

The gold is still gold, but it is now in a liquid state.



Tarnishing a piece of silver is








Tarnishing a piece of silver is





Explanation:

Tarnish transforms pure silver, Ag, into silver sulfide, Ag2S.


• An element is a material made of only one kind of atom. Pure gold is an element because it is made of only gold atoms.

• An atom is the fundamental unit of an element.

The term "element" is used when referring to macroscopic

quantities.

The term "atom" is used when discussing the submicroscopic.

Elements to Compounds


Compound Formula

Oxygen O2

Ozone O3

Sulfur S8

Gold Au


• The elemental formula is used to show the proportion by which atoms combine to form an element.



A compound is a substancethat consists of atoms ofdifferent elements.



• Compounds have properties uniquely different from the elements from which they are made.


Compound Formula

Sodium chloride NaCl

Ammonia NH3

Water H2O


• A chemical formula is used to show the proportion by which elements combine to form a compound.


• Guideline 1– Start with the element farthest to the left in the

periodic table.– For the element to the right, add the suffix -ide.

Example:

NaCl

Naming Compounds


Sodium chloride

Example:

NaCl

Na Cl

Naming Compounds


Naming Compounds

• Guideline 2– With different possible combinations of

elements, use prefixes to remove ambiguity.


mono-

di-

tri-

tetra-

1

2

3

4

Naming Compounds


Examples:

CO carbon monoxide

CO2 carbon dioxide

Naming Compounds


Examples:

H2O dihydrogen monoxide

H2O2 dihydrogen dioxide

Naming Compounds


Examples:

H2O water

H2O2 hydrogen peroxide

Naming Compounds


Naming Compounds

• Guideline 3– Common names are sometimes used for

convenience.


What is the name of the compound with the

formula CBr4?

A. chrobrofor

B. SeeBer4

C. carbon bromide

D. carbon tetrabromide


Naming CompoundsCHECK YOUR NEIGHBOR


What is the name of the compound with the

formula CBr4?

A. chrobrofor

B. SeeBer4

C. carbon bromide

D. carbon tetrabromide

Naming CompoundsCHECK YOUR ANSWER


0.2 nm

2.0 nm

• Nanotechnology is an area of applied science in which we engineer materials by manipulating objects less than 100 nanometers in size.


Two main approaches in nanotechnology:

1. Top-down: This approach is an extension of microtechnology techniques to smaller and smaller scales.

2. Bottom-up: This approach involves building nano-sized objects atom by atom.


• An important tool of the bottom-up approach is the scanning probe microscope, which detects and characterizes the surface of atoms of materials using an ultrathin probe tip.

Documents

Chapter 11 Lecture Conceptual Integrated Science Second Edition © 2013 Pearson Education, Inc. Investigating Matter