Unit 1A Introduction to Chemistry & Data Analysis

Introduction to Chemistry Objectives: Define substance. Explain the formation and importance of ozone. Identify the area of emphasis for various branches of chemistry. Identify the common steps of scientific methods. Compare and contrast types of data. Identify types of variables. Describe the difference between a theory and a scientific law.

What is Chemistry? Chemistry is the study of matter and the changes it undergoes. Chemistry incorporates the study of submicroscopic concepts and occurrences in order to explain macroscopic changes in our world. Because chemistry carries over into many other science disciplines it is referred to as the central science. What is matter? Matter is defined as anything that has mass and takes up space. Look around the room… All the “stuff” you see that is matter.

A Common Problem First of all Ozone is substance. A SUBSTANCE is also known as a chemical and is matter that has a definite composition. O 3It is a highly reactive molecule that is composed of three oxygen atoms, hence its chemical formula is O 3. Ozone is located in the Stratosphere between 9 and 18 miles above the earths surface. It as a shield from the harmful ultraviolet B radiation emitted by the sun.

A Common Problem

1950s: Research shows certain compounds ( OH and NO) could react with Ozone to cause a reduction in the overall amount of Ozone. 1970s: Molina and Rowland concluded that, like N 2 O, the CFCs would reach the stratosphere where they would be dissociated by UV light, releasing chlorine atoms. Chlorofluorocarbons (CFCs), chemicals found mainly in spray aerosols heavily used by industrialized nations CFCs were banned in 1978 for use in aerosol cans.

What is there to learn from this? Most scientific discovery begins with an observation or a problem. Scientific theories must be supported by evidence. Proper scientific research can lead to significant change.

Back to Matter Matter Matter is anything that has mass and takes up space. MassMass is a measurement that reflect the amount of matter in a object. Weight is a measurement that reflects the amount of mass an object has and the effects the force of gravity has on that object.Weight is a measurement that reflects the amount of mass an object has and the effects the force of gravity has on that object.

Care to lose a few pounds?? Some options: Go to space. Visit Mount McKinley

Chemistry the Central Science Chemistry has is typically divided into several branches that focus on specific areas of the discipline. –Organic chemistry –Inorganic chemistry –Physical chemistry –Analytical chemistry –Biochemistry –Environmental chemistry – Industrial chemistry – Polymer chemistry – Theoretical chemistry – Thermochemistry

Inorganic Chemistry

Physical Chemsitry

Analytical Chemistry

Biochemistry

Polymer chemists study large, complex molecules (polymers) that are built up from many smaller (sometimes repeating) units. They study how the smaller building blocks (monomers) combine, and create useful materials with specific characteristics by manipulating the molecular structure of the monomers/polymers used, the composition of the monomer/polymer combinations, and applying chemical and processing techniques that can, to a large extent, affect the properties of the final product. Polymer chemists are unique within the chemistry community because their understanding of the relationship between structure and property spans from the molecular scale to the macroscopic scale. Polymer Chemistry

Career Path Information Gathered From…. chemistry.html

The Scientific Method The SCIENTIFIC METHOD is a systematic approach used in scientific study. Francis Bacon proposed the first ideas on the scientific method in 17 th Century. “The discoveries which have been made in the sciences up to now are such as lie close to vulgar notions, scarcely beneath the surface. In order to penetrate into the inner and further recesses of nature, it is necessary that... a method of intellectual operation be introduced altogether better and more certain.” The SCIENTIFIC METHOD is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others.

The Scientific Method

1.Make an Observation An OBSERVATION is the act of gathering information. Qualitative Data- is obtained through observations that describe color, smell, shape, or some other physical characteristic that is related to the five senses. Quantitative Data-is obtained from numerical observations that describe how much, how little, how big or how fast.

The Scientific Method Watch the following video… What are some qualitative observations? What are some quantitative observations?

The Scientific Method 2.A HYPOTHESIS is a tentative explanation for an observed phenomenon. Rowland and Molina: “Releasing CFCs into the atmosphere would cause significant ozone depletion.” Generally a hypothesis is an “if” “then” statement. If this happens then this will be the result.

The Scientific Method 3.An EXPERIMENT is a set of controlled observations that test the hypothesis. All experiments must have at least two variables: An independent variable is the variable you plan to change. The dependent variable is the variable that changes in value in response to a change in the independent variable.

The Scientific Method 4.Collect and Analyze Data. 5.Draw a conclusion. A conclusion is a judgment based on the information obtained from the experiment.conclusion A hypothesis is never proven, only supported or discarded.

Theories and Scientific Laws A theory is an explanation that has been repeatedly supported by many experiments.theory A theory states a broad principle of nature that has been supported over time by repeated testing. Theories are successful if they can be used to make predictions that are true. Examples????

Theories and Scientific Laws A scientific law is a relationship in nature that is supported by many experiments, and no exceptions to these relationships are found.scientific law Examples???