Ch. 1--What Is Chemistry?

• 1.1—Connecting to your worldvocab (chemistry, matter, pure and applied chemistry), types of chemistry

• 1.2—Chemistry far and wide• 1.3—Thinking like a scientist

Fleming, Lavoisier, alchemy, scientific method• 1.4—Problem solving (skip)

1.1—Connecting to Your WorldChemistry is the study of the composition of matter

and the changes that matter undergoes.Matter is anything that has mass and occupies space.

Why is the scope of chemistry so vast? Because living and nonliving things are made of

matter, chemistry affects all aspects of life and most natural events.

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Areas of Study

According to this text, there are five traditional areas of study in chemistry.

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a) organic chemistryb) inorganic chemistryc) biochemistry d) analytical chemistry e) physical chemistry

These are just generalizations though. This year we will study nuclear chemistry; a topic large enough to be it’s own area of study.

Areas of Study1.1

Inorganic chemistry is the study of chemicals that, in general, do not contain carbon.

Organic chemistry is defined as the study of all chemicals containing carbon.

The study of processes that take place in organisms is biochemistry.

Areas of Study1.1

Analytical chemistry is the area of study that focuses on the composition of matter.

Physical chemistry is the area that deals with the mechanism, the rate, and the energy transfer that occurs when matter undergoes a change.

Why Study Chemistry?1.1

Chemistry can help you satisfy your natural desire to understand how things work. Chemistry can be useful in explaining the natural world, preparing people for career opportunities, and producing informed citizens. Pure research can lead directly to an application, but an application can exist before research is done to explain how it works.

Pure chemistry is the pursuit of chemical knowledge for its own sake.

Applied chemistry is research that is directed toward a practical goal or application.

Pure and Applied ChemistryNylon

– In the early 1930’s, Wallace Carothers produced nylon while researching cotton and silk.

– A team of scientists and engineers applied Carothers’s research to the commercial production of nylon.

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Aspirin—Long before researchers figured out how aspirin works, people used it to relieve pain, and doctors prescribed it for patients who were at risk for a heart attack. (ex. Hippocrates (400 B.C.) left historical records of pain relief treatments, including the use of powder made from the bark and leaves of the willow tree to help heal headaches, pains and fevers.)—In 1971, it was discovered that aspirin can block the production of a group of chemicals that cause pain and lead to the formation of blood clots. This is an example of pure research.

Pure and Applied Chemistry

Technology is the means by which a society provides its members with those things needed and desired.

– Technology allows humans to do some things more quickly or with less effort.

– There are debates about the risks and benefits of technology.

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Why Study Chemistry?

Preparing For a Career Many careers require

knowledge of chemistry. A photographer uses chemical processes to control the development of photographs in a darkroom.

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Being an Informed CitizenKnowledge of chemistry and other sciences can help you evaluate the data presented, arrive at an informed opinion, and take appropriate action.

Chemistry can help you satisfy your natural desire to understand how things work.

1. Which of these traditional areas of study mostly involve compounds containing carbon?

(1) organic chemistry

(2) inorganic chemistry

(3) biochemistry

a) (1) and (2)b) (1) and (3)c) (2) and (3)d) (1), (2), and (3)

1.1 Section Quiz.

2. Which phrase best describes applied chemistry?a) the pursuit of knowledge for its own sakeb) research that answers a general questionc) addresses fundamental aspects of a questiond) research directed toward a practical goal

1.1 Section Quiz.

3. Informed citizens are most likely to a) provide funds for scientific research.b) determine which areas of research are valid.c) decide who is qualified to do research.d) influence the development of technology.

1.1 Section Quiz.

1.2--Chemistry Far and Wide

The first tools were objects such as a stone with a sharp edge. In time, people learned to reshape these objects to produce better tools. Chemistry plays a key role in the production of new materials.

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MaterialsWhat impact do chemists have on materials, energy, medicine, agriculture, the environment, and the study of the universe?....... Chemists design materials to fit specific needs.

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•In 1948, George de Mestral took a close look at the burrs that stuck to his clothing. He saw that each burr was covered with many tiny hooks. •In 1955, de Mestral patented the design for the hook-and-loop tapes. These are used as fasteners in shoes and gloves.

This story illustrates two ways of looking at the world—the macroscopic view and the microscopic view.

Burrs belong to the macroscopic world, the world of objects that are large enough to see with the unaided eye.The hooks belong to the microscopic world, or the world of objects that can be seen only under magnification.

EnergyChemists play an essential role in finding ways to conserve energy, produce energy, and store energy.

– Conservation• One of the easiest ways to conserve energy is through insulation. Insulation acts as

a barrier to heat flow from the inside to the outside of a house or from the outside to the inside of a freezer.

– Production• The burning of coal, petroleum, and natural gas is a major source of energy. These

materials are called fossil fuels. Oil from the soybeans is used to make biodiesel.– Storage

• Batteries are devices that use chemicals to store energy that will be released as electric current.

• For some applications, it important to have batteries that can be recharged rather than thrown away. Digital cameras, wireless phones, and laptop computers use rechargeable batteries.

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Medicine and BiotechnologyChemistry supplies the medicines, materials, and technology that doctors use to treat their patients.

– MedicinesThere are over 2000 prescription drugs. Many drugs are

effective because they interact in a specific way with chemicals in cells. Knowledge of the structure and function of these target chemicals helps a chemist design safe and effective drugs.

– MaterialsChemistry can supply materials to repair or replace body parts. Artificial hips and knees made from metals and plastics can replace worn-out joints and allow people to walk again without pain.

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Medicine and Biotechnology– Biotechnology

• From 1990 to 2003, scientists worldwide worked on the Human Genome Project. They identified the genes that comprise human DNA—about 30,000. The discovery of the structure of DNA led to the development of biotechnology.

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Biotechnology applies science to the production of biological products or processes.

Agriculture– Chemists help to develop more productive crops and safer,

more effective ways to protect crops.– Productivity

• One way to track productivity is to measure the amount of edible food that is grown on a given unit of land.

• Chemists test soil to see if it contains the right chemicals to grow a particular crop and recommend ways to improve the soil.

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Chemists also help determine when a crop needs water. If the genes from a jellyfish that glows are transferred to a potato plant, the plant glows when it needs to be watered.

Agriculture– Crop Protection

• Chemists sometimes use chemicals produced by insects to fight insect pests. The plastic tube wrapped around the stem of the tomato plant contains a chemical that a female pinworm moth emits to attract male moths. It interferes with the mating process so that fewer pinworms are produced.

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The EnvironmentA pollutant is a material found in air, water, or soil that is harmful to humans or other organisms. Chemists help to identify pollutants and prevent pollution.

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Identify PollutantsUntil the mid-1900s, lead was used in many products, including paints and gasoline.A study done in 1971 showed that the level of lead that is harmful to humans is much lower than had been thought, especially for children. Even low levels of lead in the blood can permanently damage the nervous system of a growing child.

Prevent PollutionThe strategies used to prevent lead poisoning include testing children’s blood for lead, regulation of home sales to families with young children, and public awareness campaigns with posters.

The UniverseTo study the universe, chemists gather data from afar and analyze matter that is brought back to Earth.

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Chemists have analyzed more than 850 pounds of moon rocks that were brought back to Earth. Some of these rocks are similar to rocks formed by volcanoes on Earth, suggesting that vast oceans of molten lava once covered the moon's surface.

The robotic vehicle Opportunity was designed to determine the chemical composition of rocks and soil on Mars. Data collected at the vehicle’s landing site indicated that the site was once drenched with water.

1.2 Section Quiz.

1. Choose the correct words for the spaces. To meet the demand for energy, chemists find ways to __________ energy and __________ energy.

a) conserve, produceb) conserve, usec) produce, used) convert, store

1.2 Section Quiz.

2. Which of the following is an example of biotechnology?

a) using soybeans to produce biodieselb) replacing diseased arteries with plastic tubesc) testing the lead content of bloodd) transferring a jellyfish gene into a potato plant

1.2 Section Quiz.

3. To understand how a burr could stick to clothing, George de Mestral had to take which view of a burr?

a) chemicalb) materialc) macroscopicd) microscopic

1.3--Thinking Like a Scientist

In 1928, Alexander Fleming noticed that bacteria he was studying did not grow in the presence of a yellow-green mold. In 1945, Fleming shared a Nobel Prize for Medicine with Howard Florey and Ernst Chain, who led the team that isolated penicillin.

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Alchemy before ChemistryEarly chemistry is called alchemy. Alchemists developed the tools and techniques for working with chemicals. Chemistry is a systematic method of study of matter.

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Alchemists developed processes for separating mixtures and purifying chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle.

Mortar and Pestle

Antoine-Laurent Lavoisier (late 1700’s)

Lavoisier helped to transform chemistry from a science of observation to the science of measurement that it is today. He designed a balance that could measure mass to the nearest 0.0005 gram. He also showed that oxygen is required for a material to burn.

The Scientific MethodThe scientific method is a logical, systematic approach to the solution of a scientific problem.

1. Define a problem.2. Collect/gather background information.3. State a hypothesis (proposed explanation for an observation).4. Develop and conduct an experiment (procedure that is used to test a

hypothesis).5. Record observations (use your senses to obtain information)/ Analyze data6. State a conclusion(after lots of support, conclusion may become a theory OR

it might be necessary to modify the hypothesis and conduct more experiments).

The control is the part that does not change in the experiment; the variable that you change during an experiment is the manipulated variable, or independent variable; and the variable that is observed during the experiment is the responding variable, or dependent variable.

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The Scientific Method

Once a hypothesis meets the test of repeated experimentation, it may become a theory.

• A theory is a well-tested explanation for a broad set of observations

• A theory may need to be changed at some point in the future to explain new observations or experimental results

A scientific law is a concise statement that summarizes the results of many observations and experiments.

• A scientific law doesn’t try to explain the relationship it describes. That explanation requires a theory.

• Because science is based on the unknown, it is becoming an increasing trend to not use the term scientific law.

Collaboration and Communication1.3

No matter how talented the players on a team, one player cannot ensure victory for the team. Individuals must collaborate, or work together, for the good of the team.

When scientists collaborate and communicate, they increase the likelihood of a successful outcome.

Collaboration isn’t always a smooth process. You will likely work on a team in the laboratory. If so, you may face some challenges. But you can also experience the benefits of collaboration.

1.3 Section Quiz.

1. Lavoisier is credited with transforming chemistry from a science of observation to a science of

a) speculation.b) measurement.c) hypotheses.d) theories.

1.3 Section Quiz.

2. A hypothesis isa) information obtained from an experiment.b) a proposed explanation for observations.c) a concise statement that summarizes the results of

many of experiments.d) a thoroughly tested explanation for a broad set of

observations.

1.3 Section Quiz.

3. Why are articles in scientific journals the most reliable source of information about new scientific discoveries?

a) The articles are reviewed by experts in the author's field.

b) Any article that is submitted is published.c) Everyone has access to the information.d) The articles are short and easy to read.

What is chemistry?

Definition—chemistry, matterTypes of chemistryPure vs. applied chemistryWhy study chemistry?Examples of uses, careers, etc.

Alchemy vs. ChemistryScientific Method (6 steps from class notes)

Theory vs. lawControl (only change one thing in an experiment)Independent vs. dependent variables (manipulative and responding)

Alexander Fleming and Antoine-Laurent Lavoisier

What you need to know: Chapter 1