Introduction to Chemistry Chapter 1

1.2 Why Study Chemistry? All the “stuff” in the universe is made from building blocks. These building blocks and everything made from them are called matter. Chemistry is the study of matter, its properties, and the changes it undergoes. Has a definite affect on everyday life - taste of foods, grades of gasoline, etc.

1.2 Why Study Chemistry? Everyone and everything around us involves chemistry – explains our world. Helps you make choices; helps make you a better informed citizen. A possible career for your future.

1.2 Matter and its Characteristics Matter has many different forms. Mass is a measurement that reflects the amount of matter. Weight is a measure of mass and the force of gravity on an object. Weight can change from place to place, but mass is constant.

1.2 Chemistry and Matter A substance, also known as a chemical, is matter that has a definite composition. Examples: Breathable Oxygen, O2, is made up of 2 oxygen atoms. Ozone, O3, is a substance in the atmosphere made up of 3 oxygen atoms. Water, H2O, is made up of 2 hydrogen atoms and 1 oxygen atom

1.2 Matter and It’s Characteristics Much of matter and its behavior is macroscopic, meaning that it can be observed without a microscope. The structure, composition, and behavior of all matter can be described on the submicroscopic (atomic) level.

1.2 Matter and its Characteristics Chemistry explains events on the atomic level that cause macroscopic observations. A model is a verbal, visual, or mathematical explanation of experimental data.

1.2 Chemistry: The Central Science Chemistry is traditionally broken into branches that focus on specific areas such as: Organic chemistry Inorganic chemistry Physical chemistry Analytical chemistry Biochemistry Environmental chemistry Industrial chemistry Polymer chemistry Theoretical chemistry Thermochemistry

1.2 Branches of Chemistry

1.2 Check _____ is anything that has _____ and takes up space. A. Weight; mass B. Mass; matter C. Matter; weight D. Matter; mass

1.2 Check Chemistry tries to explain _____ observations based on _____ observations. A. atomic; submicroscopic B. macroscopic; nuclear C. macroscopic; submicroscopic D. microscopic; macroscopic

1.3 Scientific Methods The scientific method is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science. It is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others.

1.3 A Systematic Approach The steps in a scientific method are repeated until a hypothesis is supported or discarded.

1.3 A Systematic Approach 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.

1.3 A Systematic Approach A hypothesis is a proposed, testable, explanation for what has been observed. **NOT AN EDUCATED GUESS** An experiment is a set of controlled observations that test the hypothesis.

1.3 A Systematic Approach A variable is a quantity or condition that can have more than one value. An independent variable is the variable you plan to change in an experiment. The dependent variable is the variable that changes in value in response to a change in the independent variable.

1.3 A Systematic Approach A control is a standard for comparison in the experiment. A conclusion is a judgment based on the information obtained from the experiment. A hypothesis is never proven, only supported or discarded. A model can be used to make predictions.

Steps in the Scientific Method 1. Observations (uses your 5 senses) a) quantitative involves numbers = 95oF b) qualitative is word description = hot 2. Formulating hypotheses (ideas) - a testable possible explanation for the observation, NEVER “educated” guess 3. Performing experiments (the test) - gathers new information to help decide whether the hypothesis is valid

Steps in the Scientific Method Performing experiments (the test) - gathers data and observations to help decide whether the hypothesis is valid A controlled experiment is designed to test the hypothesis. Analyze and Conclude - Determine whether your data and observations either: A) Support your hypothesis B) Do not support your hypothesis 5. Modify hypothesis and repeat the cycle.

1.3 Theory and Scientific Law A theory is an explanation that has been repeatedly supported by many experiments. 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.

1.3 Theory and Scientific Law (cont.) A scientific law (or natural law) is a relationship in nature that is supported by many experiments, and no exceptions to these relationships are found.

1.3 Check Quantitative data describes observations that are _____. A. numerical B. conditions C. independent D. hypotheses

1.3 Check Scientific methods are _____ approaches to solving problems. A. dependent B. independent C. hypothetical D. systematic

1.4 Types of Scientific Investigations Pure research is research to gain knowledge for the sake of knowledge itself. Applied research is research undertaken to solve a specific problem in fields like medicine, agriculture, and manufacturing – leads to an application. Chance discoveries occur when scientists obtain results that are far different from what they expected.

1.4 The Benefits of Chemistry Technology is the practical use of scientific information concerned with making improvements in human life and the world around us. Chemists solve many real problems we face today such as: Ozone depletion Finding cures for diseases Reducing the weight of cars Nylon Aspirin (C9H8O4) - to relieve pain

1.4 Lab Safety You are responsible for your safety and the safety of others around you. Refer to Table 1.2 on page 16 of your textbook for a list of safety rules in the the laboratory.

1.4 Check What are accidental discoveries, like penicillin, called? A. applied discoveries B. chance discoveries C. pure discoveries D. Newton’s Law

1.4 Check What kind of research solves specific problems? A. pure B. exploratory C. applied D. model

A Brief History of Chemistry The word chemistry comes from alchemy practiced in China and India since 400 B.C. developed the tools and techniques for working with chemicals Alchemy has two sides: Practical: techniques for working with metals, glass, dyes, etc. Mystical: concepts like perfection – gold was a perfect metal

A Brief History of Chemistry In the 1500s, a shift started from alchemy to science – King Charles II was a supporter of the sciences Royal Society of London for the Promotion of Natural Knowledge Encouraged scientists to use more experimental evidence, and not philosophical debates

A Brief History of Chemistry In the late 1700s, Antoine Lavoisier helped transform chemistry from a science of observation to the science of measurement – still used today He settled a long-standing debate about burning, which was… Oxygen was required!

A Brief History of Chemistry

Chemistry Far and Wide Chemists design materials to fit specific needs – velcro (Patented in 1955) perfume, steel, ceramics, plastics, rubber, paints, nonstick cooking utensils, polyester fibers Two different ways to look at the world: macroscopic and microscopic

Chemistry Far and Wide Energy – we constantly have greater demands We can conserve it; use wisely We can try to produce more; oil from soybeans to make biodiesel fossil fuels, solar, batteries (that store energy – rechargeable?), nuclear (don’t forget pollution!)

Chemistry Far and Wide Medicine and Biotechnology- Supply materials doctors use to treat patients vitamin C, penicillin, aspirin (C9H8O4) materials for artery transplants and hipbones bacteria producing insulin

Chemistry Far and Wide Medicine and Biotechnology- Supply materials doctors use to treat patients vitamin C, penicillin, aspirin (C9H8O4) materials for artery transplants and hipbones bacteria producing insulin

Chemistry Far and Wide Agriculture Produce the world’s food supply Use chemistry for better productivity – soil, water, weeds plant growth hormones ways to protect crops; insecticides disease resistant plants

Chemistry Far and Wide The Environment both risks and benefits involved in discoveries Pollutants need to be 1) identified and 2) prevented Lead paint was prohibited in 1978; Leaded gasoline? Drinking water? carbon dioxide, ozone, global warming

Chemistry Far and Wide The Universe Need to gather data from afar, and analyze matter brought back to Earth composition of the planets analyze moon rocks planet atmospheres life on other planets?

Ch 1 Assessment Which of the following has a definite composition? A. building block B. variable C. substance D. mixture

Ch 1 Assessment What varies with changes in gravitational force? A. matter B. weight C. mass D. composition

Ch 1 Assessment Which of the following would be an example of quantitative data? A. blue socks B. square peg C. six kilograms D. loud noise

Ch 1 Assessment Which of the following is an example of qualitative data? A. 1.35 kilograms B. red flower C. eight pieces D. three kilometers

Ch 1 Assessment What is the discovery of nylon an example of? A. pure research B. applied research C. variables D. chance discovery

Ch 1 Assessment _____ is/are anything that has mass and takes up space. A. Solids B. Building block C. Forces D. Matter

Ch 1 Assessment Which type of variables are controlled by the scientist? A. independent B. dependent C. pure D. response

Ch 1 Assessment Weight is a measure of _____ and _____. A. force; gravity B. mass; gravity C. matter; mass D. gravity; motion

Ch 1 Assessment Producing heat resistant plastics is an example of what kind of research? A. independent B. dependent C. pure D. applied

Ch 1 Assessment Which of the following describes a systematic approach to solving problems? A. pure research B. hypothetical method C. theoretical method D. scientific method