Chapter One INTRODUCTION TO CHEMISTRY

The Hindenburg Disaster The Hindenburg Disaster

The Hindenburg Disaster at its mooring station. May 6, 1937.

At 7:25 p.m. local time, the Hindenburg caught fire and quickly became engulfed in flames

Destruction time of about 16 seconds (245m / 15m/s = 16.3s).

Of the 97 people on board, 35 people died in addition to one fatality on the ground.

Happy Birthday !!  Do you want YOUR Birthday balloons filled with Hydrogen or Helium?  Knowing about  Chemistry might help  you make that decision!!!

Chemistry involves the entire Universe!!  All the “stuff” that makes up the universe is matter. Chemistry - the study of matter and the changes it undergoes.

Section 1.2 Chemistry and Matter

An understanding of Chemistry is basic to ALL Sciences.

 Matter- anything that has mass and takes up space

 Mass- the amount of matter in an object.

What things are NOT matter?  Ideas  Heat  Light  radio waves  magnetic fields

Weight  Weight- measure of the amount of matter and effect of Earth’s gravitational pull on an object.

Weight vs. Mass Weigh more at Sea Level. Weigh less on a mountain.. In space “weightless” MASS REMAINS THE SAME!!!!!

Can’t always See it! Submicroscopic- so tiny that parts can’t even be seen with microscope (ex: atom)  So we often use models for a visual representation of objects.

Branches of Chemistry 1. Organic Chemistry 1. Organic Chemistry Study of carbon containing chemicals Study of carbon containing chemicals

2. Inorganic Chemistry Study of matter that Study of matter that does not contain carbon

3. Physical Chemistry Study of the behavior and changes of matter and the related energy changes

4. Analytical Chemistry Study of components and composition of substances

5. Biochemistry Study of matter and processes of living organisms

Section 1.3 Scientific Methods

Scientific Method- a systematic approach used in all scientific study a systematic approach used in all scientific study

Steps of Scientific Method 1. Observation - the act of gathering information.

Observations  Qualitative data – describes a physical characteristic or relates to the 5 senses  Examples: how it looks, feels, sounds, tastes, color, odor and shape.

 Quantitative data numerical information  Examples: measure of temperature, pressure, and volume.

2. Hypothesis – is a tentative explanation for what has been observed.

3.Experiment - set of controlled observations that test the hypothesis.

Parts of an Experiment

Independent variable - variable you are testing Dependent variable - changes, and can be measured

 The independent variable is the light.  The dependent variable is how much oxygen is produced.

Constant – factors that are not allowed to change Control - standard for comparison

 Constants - The water and the plant remain the same in both experiments.  The control is just like the experiment, but does Not contain the independent variable.

Variables Independent Variable – What is Tested Dependent Variable – What I observe/measure Constants– Stays the Same Control – What I use to Compare

Variable Exercise Instructions  Fold a blank sheet of paper in three parts, like when mailing a letter.  At the top of each column write the following headings: Independent Variable, Dependent Variable and the Constants.

Question #1  How fast does a candle burn? Question #2  Is a classroom noisier when the teacher leaves the room? Question #3  Does fertilizer make a plant grow bigger?

Key to Variable Activity with Power Point Chapter 1 Question Independent Variable Dependent Variable Constants #1 How fast does a candle burn? Record time in minutes Height of candle measured in cm every 5 minutes. No wind. Use same type of candle #2 Is the classroom noisier. When the teacher leaves. The room? The teacher is either in the room or not. Loudness measured in decibels Same classroom. Same students. Same time of day #3 Does fertilizer make a plant. Grow bigger? Amount of fertilizer Height of plant is measured. Number of leaves counted Same size pots. Same kind of plant. Same type and amount of soil. Same amount of water and light

Variables Remember this phrase: DRY MIX

Dependent Variable DRY Dependent Variable The variable that Responds Graphed on the Y-axis

Independent Variable MIX The variable Manipulated by the scientist Independent variable Graphed on the X-axis

Record and Analyze Data 4.Data – must be recorded and analyzed.  Usually with Data tables and Graphs.

5.Conclusion – a judgment based on the information obtained. A hypothesis can be supported but not proven!

 Model – a visual, verbal, and/or mathematical explanation of experimental data.  For something too BIG or too small to be seen.

Theory- an explanation supported by many, many experiments.  Ex: Theory of Relativity Scientific Law- a conclusion about certain relationships in nature.  Ex: Law of Gravity

Scientific Method and Law

Section 1.4 Scientific Research Types of Scientific Investigations  Pure Research- seeks to gain knowledge for the sake of knowledge  Applied Research- research undertaken to solve a specific problem

Lab Safety – YOU are responsible for your safety and the safety of those around you!!!

Benefits of Chemistry  Products of chemistry make our lives easier and more comfortable  Technology- the practical use of scientific information.