Chemistry 103

Instructor: Dr. David W. Hatchett

Lecture 1

OUTLINE

• Introduction to Course• What is Chemistry?

– Matter defined– Physical vs. Chemical

• Historical Perspectives• The Scientific Method• The Periodic Table

Outline

• Mathematics of Chemistry (Measurements)– Units– Significant Figures (Sig Figs)– Calculations & Sig Figs– Scientific Notation– Dimensional Analysis

Course Introduction

• Dr. David W. Hatchett• Office CHE 213• Office Hours: 1:30 – 3:00 pm daily, or by

appointment.• E-mail: david.hatchett@unlv.edu• Phone: 895-3509

Introduction to Course

• Purpose of Course

Introduction to Course

• Academic Success Center

• http://academicsuccess.unlv.edu/

Introduction to Course

• Course Resources• Website

Web Lectures and homework

• Website (downloadable materials.)• http://sciences.unlv.edu/Chemistry/Hatchett/

Weblectures

Syllabus

Homework

Introduction to Course

• Homework• Quizzes• Three Exams

(last one comprehensive)

Introduction to Course

• Purpose of Course• Academic Success• Grading

Grading Scale

• GRADING: This course is graded on a letter grade basis only (no S/F grade). Your final grade will be based on three exams (300 points) and quizzes (50 points). The following grading scale will be used:

A 100 – 90% B 89-80% C 79-70% D 69-60% F 56-0%

– TOTAL: 350 points; percentage = [(your points)/350] x 100

Chemistry Success

• Complete Homework• Seek Help during

office hours• Form study groups• Don’t become overly

confident with early material.

• Don’t cram before an exam.

The “good and evil” of chemistry

Physics Chemistry Biology

Scientific Overlap

Physical

Analytical

Inorganic

Organic

Biochemistry

What is Chemistry?

Chemistry is the study of Matter.

What is Matter?

Matter is anything that has mass and takes up

space.

What is Matter?

Matter is anything that has mass and takes up

space.

What is Matter?

Matter has both physical and chemical

properties

Physical Properties

Physical properties are:

• Characteristics observed or measured without changing the identify of a substance.

• Shape, physical state, odor, boiling and freezing points, density, and color of that substance.

States of Matter

All substances known as matter exist inone of three forms or states:• Solids

Have definite volumes and shapes• Liquids

Have definite volumes, but take the shapes of containers

• GasesHave no definite volumes or shapes

Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Physical Properties of Copper

Copper has physical properties:

• Reddish-orange

• Very shiny

• Excellent conductor of heat and electricity

• Solid at 25C• Melting point 1083C• Boiling point 2567C Copyright © 2005 by Pearson Education, Inc.

Publishing as Benjamin Cummings

Chemical Properties

Chemical properties describe the ability of a substance

• To interact with other substances• To change into a new substance

Example:

Iron has the ability to form rust

when exposed to oxygen. Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings

Chemistry 103

This course serves as introduction into the world of chemistry, and includes both chemical and physical processes.

Historical Perspective

• Ancient Greeks and the 4 basic elements:

Historical Perspective

• Ancient Greeks and the 4 basic elements:

Air,

Historical Perspective

• Ancient Greeks and the 4 basic elements:

Fire,

Historical Perspective

• Ancient Greeks and the 4 basic elements:

Water

Historical Perspective

• Ancient Greeks and the 4 basic elements:

&

Earth.

Historical Perspective

• Ancient Greeks and the 4 basic elements:

Air,

Fire,

Water &

Earth.

Historical Perspectives

Alchemists

• Attempted to turn base metals into gold

• Attempted to find the “Exilir of Life”

Scientific Method

The scientific method is the process used by scientists to explain observations in nature.

Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings

Scientific Method

The scientific method involves:

• Making Observations

• Writing a Hypothesis

• Doing Experiments

• Proposing a Theory

Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings

Summary of the Scientific Method

Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings

Periodic Table

Primary resource for a chemist as well as other scientists.

Lists all the known elements in a “periodic way”

Element - a substance that can not be broken down into simpler substances by chemical means.

Periodic Table

Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings

Symbols for the Elements

• H

• O

• Ag

• Au

• Hg

• He

• Na

Symbols for the Elements

• H Hydrogen

• O Oxygen

• Ag Silver

• Au Gold

• Hg Mercury

• He Helium

• Na Sodium

Chemical Progression

Atoms ---> Compounds ---> Chemical Reactions

Measured vs Exact numbers

• Scientists make many kinds of measurements– The determination of the dimensions, capacity, quantity or extent

of something– Length, Mass, Volume, Density

• All measurements are made relative to a standard• All measurements have uncertainty

Units and Measurements

Systems of Measurement

• English System– Common measurements– Pints, quarts, gallons, miles, etc.

• Metric System– Units in the metric system consist of a base unit

plus a prefix.

Metric Base Units

Exact (Defined) and Inexact (Measured) Numbers

• Exact numbers– Have no uncertainty associated with them

– They are known exactly because they are defined or counted

– Example: 12 inches = 1 foot

• Measured numbers– Have some uncertainty associated with them

– Example: all measurements

Accuracy vs. Precision

Accuracy

How closely a measurement comes to

the true, accepted value

Precision

How closely measurements of the same quantities come

to each other

Significant FiguresAre the digits in any measurement known with certainty, plus one digit that is uncertain.

Measured numbers convey

*Magnitude*Units

*Precision