Introduction to Chemistry

Section 1: A Story of Two Substances

Section 2: Chemistry and Matter

Section 3: Scientific Methods

Section 4: Scientific Research

• Section 1: Chemistry is the study of everything around us.

• Section 2: Branches of chemistry involve the study of different kinds of matter.

• Section 3: Scientists use scientific methods to systematically pose and test solutions to questions and assess the results of the tests.

• Section 4: Some scientific investigations result in the development of technology that can improve our lives and the world around us.

Review• matter• technology• systematic approach• synthetic

New continued• quantitative data• hypothesis• experiment• independent variable• dependent variable• control• conclusion• theory• scientific law• pure research• applied research

Vocabulary

New• chemistry• substance• mass• weight• model• scientific method• qualitative data

A Story of Two Substances

Section 1

• Chemistry is the study of everything around us.

Section 1: A Story of Two Substances

KWhat I Know

WWhat I Want to Find Out

LWhat I Learned

Why Study Chemistry?

• All the “stuff” in the universe is made from building blocks formed in stars.

• These building blocks and everything made from them are called _______.

• ____________is the study of matter and the changes it undergoes.

The Ozone Layer

• Ultraviolet _________ damages living organisms.

• Earth’s atmosphere contains a layer of _______ that absorbs most ultraviolet radiation and protects living organisms.

• Ozone is a substance in the atmosphere made up of ____________.

• A ____________, also known as a chemical, is matter that has a definite composition.

The Ozone Layer

• Earth’s atmosphere consists of several layers. The protective ozone layer is located in the ________________.

The Ozone Layer

• Ozone, in the stratosphere, is formed when oxygen gas (O2) is exposed to ultraviolet radiation.

The Ozone Layer

• Ozone has interested and been studied by scientists since the late 1800’s.

• Ozone forms over the ________, where the rays of sunlight are the strongest and then flows towards the poles, thus, making it a convenient marker to follow the flow of air in the stratosphere.

The Ozone Layer

The Ozone Layer

• In the mid-1980s, Scientists detected thin areas in the ozone layer over _____________.

• What could be causing the ozone hole?

Chlorofluorocarbons

• In the 1920’s, large-scale production of refrigerators began, which used ammonia as coolant.

• In an attempt to find safer coolant, chemist, Thomas Midgley, Jr. synthesized the first chlorofluorocarbons in 1928.

• A Chlorofluorocarbon (CFC) is a substance that consists of _________, _______and _________.

• All substances that are classified as CFCs are:

– Man-made (they do not occur naturally)

– Nontoxic

– Stable (they do not readily react with other substances)

• Because of being nontoxic and very __________, they seemed to be ideal coolants for refrigerators and AC units, for use in plastic foams and as propellants in spray cans.

Chlorofluorocarbons

• CFCs were first detected in the atmosphere in the 1970s, and the concentrations continued to increase through the 1990s.

• Could there be a connection between ozone thinning and increasing CFCs in the atmosphere?

Review

Essential Questions

• What is a substance?

• How does ozone form and why is it important?

• What are chlorofluorocarbons and how do they get into the atmosphere?

Vocabulary• chemistry • substance

Chemistry and Matter

Section 2

• Branches of chemistry involve the study of different kinds of matter.

Section 2: Chemistry and Matter

KWhat I Know

WWhat I Want to Find Out

LWhat I Learned

Matter and its characteristics

• Matter is anything that has ______________ and takes up ____________.

• __________is a measurement that reflects the amount of matter.

• __________is a measure of mass and force of gravity on an object. Weight can change from place to place, but mass is constant.

• Much of matter and its behavior is macroscopic, meaning that it can be observed without a ________________.

• The structure, composition, and behavior of all matter can be described on the submicroscopic (________________) level.

• Chemistry explains events on the atomic level that cause ____________ observations.

• A _________is a verbal, visual, or mathematical explanation of experimental data.

Chemistry: The Central Science

• A basic understanding of chemistry is central to all sciences – biology, physics, Earth science, ecology, etc. Chemistry is traditionally broken into ________________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

Match what you think is the branch of chemistry to its area of emphasis (start with what you do know)

Branch

• Analytical chemistry

• Industrial chemistry

• Physical chemistry

• Biochemistry

• Inorganic chemistry

• Polymer chemistry

• Thermochemistry

Area of Emphasis• Most carbon-containing chemicals• In general, matter that doesn’t

contain carbon• The behavior and changes of matter

and the related energy changes• Components and composition of

substances• Matter and processes of living

organisms• Matter and the environment• Chemical processes in industry• Polymers and plastics• Chemical interactions• Heat involved in chemical processes

Review

Essential Questions

• How do mass and weight compare and contrast?

• Why are chemists interested in a submicroscopic description of matter?

• What defines the various branches of chemistry?

Vocabulary• Mass• weight

• model

Scientific Methods & ResearchSection 3 & Section 4

• Scientists use scientific methods to systematically pose and test solutions to questions and assess the results of the tests.

• Some scientific investigations result in the development of technology that can improve our lives and the world around us.

Section 3 & 4: Scientific Methods & Research

KWhat I Know

WWhat I Want to Find Out

LWhat I Learned

A Systematic Approach

• The ___________________is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science.

• It is an organized _________used by scientists to do research, and provides methods for scientists to verify the work of others.

• The steps in a scientific method are repeated until a hypothesis is supported or ______________.

A Systematic Approach

• An observation is the act of gathering information.– _____________is obtained through observations that describe color, smell, shape, or

some other physical characteristic that is related to the 5 senses.

– _______________is obtained from numerical observations that describe how much, how little, how big, or how fast.

• A _______________is a tentative explanation for what has been observed.

• An ______________is a set of controlled observations that test the hypothesis.

A Systematic Approach

• A ____________is a quantity or condition that can have more than one value.

– An ___________________________is the variable you plan to change.

– The __________________is the variable that changes in value in response to a change in the independent variable

• EXAMPLE: If you were trying to determine if temperature affects bacterial growth, you would expose different petri dishes of the same bacteria to different temperatures

– Temperature is your __________________________________

– Bacteria growth is your ___________________________________

A Systematic Approach

• A _______________is a standard for comparison in the experiment.

• During clinical drug trials, physicians will use a double-blind study. They use 2 statistically identical groups of patients. 1 will receive the drug and 1 will receive a placebo (_________). Neither patient or physician know which group receives the drugs.

• The group receiving the placebo is the control group.

• A ______________is a judgment based on the information obtained from the experiment.

– A hypothesis is never proven, only supported or discarded.

Experiments

Theory and Scientific Law

• A _________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.

• A _________________is a relationship in nature that is supported by many experiments, and no exceptions to these relations are found.

Types of Scientific Investigations

• ____________is research to gain knowledge for the sake of knowledge itself.

• _______________is research undertaken to solve a specific problem.

• Change discoveries occurs when scientists obtain results that are far different from what they expected.

– Sometimes accidents are better! Alexander Fleming’s discovery of Penicillin has saved millions.

Review

Essential Questions

• What are the common steps of scientific method?

• What are the similarities and differences between qualitative data and quantitative data?

• In an experiment, which variable is the independent variable, which is the dependent variable, and which are controls?

• What is the difference between a scientific theory and a scientific law?

• How do pure research, applied research, and technology compare and contrast?

Vocabulary• Scientific method• Qualitative data• Quantitative data• Hypothesis• Experiment• Independent

variable• Dependent

variable

• Control• Conclusion• Theory• Scientific law• Synthetic• Pure research• Applied research