Introduction to Chemistry 1.1 Chemistry and Matter 1.2 Scientific Method 1.3 Scientific Research

1.1 Chemistry and Matter Objectives Define chemistry and matter. Compare and contrast mass and weight. Explain why chemists are interested in a submicroscopic description of matter.

Chemistry: The Central Science Chemistry is the study of matter and the changes that it undergoes. Chemistry is central to all other sciences and also to our lives.

Matter and its Characteristics Matter is anything that takes up space and has mass. Mass in the measure of the amount of matter that an objects contains.

Is there a Difference Between Mass and Weight?

Yes Weight takes into account gravitational forces. Your weight would be different on the moon than on Earth. Earth 9.8 m/s2 Moon 1.62 m/s2 Mercury 3.7 m/s2 Mars 3.711 m/s2 Venus 8.87 m/s2 Jupiter 24.92 m/s2 Saturn 10.44 m/s2 Neptune 11.15 m/s2 Sun 274 m/s2

Views of Matter Macroscopic - you can see with the unaided eye. Ex. An apple Microscopic – you need the aide of a microscope to see, to small to see with out assistance. Ex. Bacteria Submicroscopic – so small that currently there is not a microscope strong enough to see the detail. Ex. Atoms

Submicroscopic View of Atoms All matter is made up of atoms. Atoms are the smallest building blocks of matter. However, they are too small for us to see. We must use models to understand what is happening in an atom. Model is a thinking device that helps explain data of experiments. How small are we talking well…. In a drop of water there are approximately If you are using a pencil, the period at the end of a sentence contains

Branches of Chemistry Branch Area of Emphasis Examples Organic Chemistry Most carbon-containing chemicals Pharmaceuticals, plastics Inorganic Chemistry In general, matter that does not contain carbon Minerals, metals, and nonmetals, semiconductors Physical Chemistry The behavior and changes of matter and the related energy changes Reactions rates, reaction mechanisms Analytical Chemistry Components and composition of substances Food nutrients, quality control Biochemistry Matter and processes of living organisms Metabolism, fermentation

1.2 Scientific Methods Objectives Identify the common steps of scientific methods. Compare and Contrast types of data. Compare and contrast types of variables Describe the difference between a theory and a scientific law.

Scientific Method The scientific method is a systematic approach used in scientific study. It is a step-wise process used to solve problems or answer questions. It is important that it be detailed, so that it can be repeated and confirmed by other scientists.

Steps Observation Research Hypothesis Experiment Analysis Conclusion

Observation Observations are made by being aware of the world around you. Questions arise from these observations. Qualitative – Observation made that describes the color, odor, shape, or physical characteristic. It is made without a measurement. Quantitative – Observation made with the use of measurement; such as temperature or mass.

Research It is important to research the topic you are questioning. See what has already been done on this topic. Helps you to develop your hypothesis.

Hypothesis Hypothesis is a possible explanation for a set of observations. A educated guess. Should be in the “If…then” format If (independent variable), then (dependent variable)

Experiment The experiment is a step-wise procedure of how you are going to test your hypothesis. It should be detailed, so it can be repeated. Needs a control and experimental group. It should include one independent variable. Independent variable – variable being manipulated or changed. Dependent variable – the variable that changes in response to the independent variable

Analysis This is the data that has been collected during the experiment. Organize the data in charts. Use graphs and diagrams to represent the results.

Conclusion Restate the hypothesis. Summarize results. Have you supported your hypothesis or not? Discuss how your results support (or don’t) your hypothesis. Areas of further research.

Theory vs. Scientific Law Hypothesizes may require adjustments as new information becomes available. When a hypothesis has been tested and supported by multiple experimentation it becomes a theory. Theories may also require revisions. Scientific law – fact of nature that is accepted as truth. Scientists use experiments and theories to explain scientific laws.

1.3 Scientific Research Objectives Compare and contrast pure research, applied research, and technology. Apply knowledge of laboratory safety.

Pure Research Pure research seeks to gain knowledge for the sake of knowledge itself. Human microbiome

Applied Research Applied research is done to solve a specific problem. Cure for cancer Sometimes the results of our research is different then we intended and lead to new wonderful discoveries.

Nylon In 1928 E.I. DuPont de Nemours and Company appointed Wallace Carothers to their new research center. He was to develop a artificial fiber similar to cellulose and silk. In 1930 Julian Hill ( a member of the team) dipped a hot glass rod in a mixture of solutions and unexpectedly pulled out long fibers. Nylon replaced silk in parachutes during WWII.