1.1: Chemistry and Chemicals

Chemistry: The study of the composition, structure, properties, and reactions of matter.
Matter: The substances that make up our world.
Chemical: A substance that always has the same composition and properties wherever it is found.
Chemical processes take place in chemistry laboratories, manufacturing plants, and pharmaceutical labs as well as every day in nature and in our bodies.

Chemical	Function
Calcium carbonate	Used as an abrasive to remove plaque
Sorbitol	Prevents loss of water and hardening of toothpaste
Sodium lauryl sulfate	Used to loosen plaque
Titanium dioxide	Makes toothpaste white and opaque
Triclosan	Inhibits bacteria that cause plaque and gum disease
Sodium fluorophosphate	Prevents formation of cavities by strengthening tooth enamel with fluoride
Methyl salicylate	Gives toothpaste a pleasant wintergreen flavor

1.2: Scientific Method: Thinking Like a Scientist

Scientific Method: A set of general principles that helps to describe how a scientist thinks.

Observations: Information determined by noting and recording a natural phenomenon.
- The first step in the scientific method is to make observations about nature and ask questions about what you observe.
Hypothesis: An unverified explanation of a natural phenomenon.
- Propose a hypothesis, which states a possible explanation of the observations. The hypothesis must be stated in such a way that it can be tested by experiments.
Experiments: A procedure that tests the validity of a hypothesis.
- Several experiments may be done to test the hypothesis.
Conclusion: An explanation of an observation that has been validated by repeated experiments that supports a hypothesis.
- When the results of the experiments are analyzed, a conclusion is made as to whether the hypothesis is true or false.
- When experiments give consistent results, the hypothesis may be confirmed.

Identifying Place Values
- For any number, we can identify the place value for each of the digits in that number.
- These place values have names such as the one's place.
Using Positive and Negative Numbers in Calculations
- Positive Number: Any number that is greater than zero and has a positive sign.
- Negative Number: Any number that is less than zero and is written with a negative sign.
Calculating a Percentage
- To determine a percentage, divide the parts by the total (whole) and multiply by 100%.
- When a value is described as a percentage, it represents the number of parts of an item in 100 of those items.
Solving Equations: In chemistry, we use equations that express the relationship between certain variables.
Interpreting a Graph
- Graph: Represents the relationship between two or more variables.
Writing Numbers in Scientific Notation
- Scientific Notation: A way of expressing numbers that are too large or too small to be conveniently written in decimal form. It has two parts:
  - a coefficient; and
  - A power of 10.

Chemistry: The study of the composition, structure, properties, and reactions of matter.
Matter: The substances that make up our world.
Chemical: A substance that always has the same composition and properties wherever it is found.
Chemical processes take place in chemistry laboratories, manufacturing plants, and pharmaceutical labs as well as every day in nature and in our bodies.

Chemical	Function
Calcium carbonate	Used as an abrasive to remove plaque
Sorbitol	Prevents loss of water and hardening of toothpaste
Sodium lauryl sulfate	Used to loosen plaque
Titanium dioxide	Makes toothpaste white and opaque
Triclosan	Inhibits bacteria that cause plaque and gum disease
Sodium fluorophosphate	Prevents formation of cavities by strengthening tooth enamel with fluoride
Methyl salicylate	Gives toothpaste a pleasant wintergreen flavor

Scientific Method: A set of general principles that helps to describe how a scientist thinks.

Observations: Information determined by noting and recording a natural phenomenon.
- The first step in the scientific method is to make observations about nature and ask questions about what you observe.
Hypothesis: An unverified explanation of a natural phenomenon.
- Propose a hypothesis, which states a possible explanation of the observations. The hypothesis must be stated in such a way that it can be tested by experiments.
Experiments: A procedure that tests the validity of a hypothesis.
- Several experiments may be done to test the hypothesis.
Conclusion: An explanation of an observation that has been validated by repeated experiments that supports a hypothesis.
- When the results of the experiments are analyzed, a conclusion is made as to whether the hypothesis is true or false.
- When experiments give consistent results, the hypothesis may be confirmed.

Identifying Place Values
- For any number, we can identify the place value for each of the digits in that number.
- These place values have names such as the one's place.
Using Positive and Negative Numbers in Calculations
- Positive Number: Any number that is greater than zero and has a positive sign.
- Negative Number: Any number that is less than zero and is written with a negative sign.
Calculating a Percentage
- To determine a percentage, divide the parts by the total (whole) and multiply by 100%.
- When a value is described as a percentage, it represents the number of parts of an item in 100 of those items.
Solving Equations: In chemistry, we use equations that express the relationship between certain variables.
Interpreting a Graph
- Graph: Represents the relationship between two or more variables.
Writing Numbers in Scientific Notation
- Scientific Notation: A way of expressing numbers that are too large or too small to be conveniently written in decimal form. It has two parts:
  - a coefficient; and
  - A power of 10.