Comprehensive Study Notes on Foundations of Chemistry and Measurement

Chemistry: The study of matter and the energy changes associated with it.
Chemical: Any substance with a definite composition.
Matter: Anything that has mass and takes up space (volume).
Mass: A measure of the amount of material that makes up an object or substance.
Volume: The amount of space occupied by an object.
Weight: A measure of the force with which gravity pulls on matter.
Quantity: Something that has magnitude, size, or amount.
System: A specific portion of matter in a given region of space that has been selected for study.

Atom: The smallest unit of an element that maintains the identity of that element.
Element: A pure substance that cannot be broken down into simpler, stable substances.
Compound: A pure substance that can be broken down into simpler, stable substances.
Mixture: A blend of two or more types of matter, each of which retains its own identity and properties.
Family: Elements in a group on the periodic table.
Extensive Property: Dependent on the amount of substance present.
Intensive Property: Independent on the amount of matter present.
Physical Property: Can be observed or measured without changing the identity of the substance.
Chemical Property: Relates to a substance’s ability to undergo changes that transform it into different substances.

Physical Change: Change in a substance that does not involve a change in the identity of a substance.
Change of State: Change of matter from one state to another.
Gas: Matter that has an indefinite volume and an indefinite shape.
Liquid: Matter that has a definite volume and indefinite shape.
Plasma: Matter that has a high temperature and is made up of charged particles.
Chemical Change: A change in which one or more substances are converted into different substances.
Chemical Reaction: A change in which at least one new substance is formed.
Reactant: Substances that react in a chemical change.
Products: Substances that are formed by the chemical change.

SI: A single measurement system called Le Systeme International d’Unites (International System of Units).
Derived Unit: Formed by multiplying or dividing standard units.
Density: Ratio of mass to volume; the mass of a substance divided by its volume ( $\text{Density} = \frac{\text{Mass}}{\text{Volume}}$ ).
Conversion Factor: Ratio derived from a relationship between two different units that can be used to convert from one unit to the other.
Dimensional Analysis: A mathematical technique that allows you to use units to solve problems involving measurements.
Directly Proportional: When two quantities are divided by one another a constant value is given ( $\frac{y}{x} = k$ ). For example, as one quantity increases, the other increases.
Inversely Proportional: When two quantities are multiplied by each other a constant value is given ( $x \times y = k$ ). For example, as one quantity increases, the other decreases.

Accuracy: How close a measurement is to the correct or accepted value.
Precision: The closeness of a set of measurements of the same quantity made in the same way.
Percentage Error: A value in which an experimental measurement is different from an accepted value.
Significant Figures: A measurement in which all of the digits known with certainty plus one final digit that is estimated.
Scientific Notation: A way of expressing very small or very large numbers written in the form of $M \times 10^n$ , where $M$ is greater than or equal to $1$ and less than $10$ ( $1 \le M < 10$ ), and $n$ is a whole number.

Scientific Method: A logical approach to solving problems through data collection.
Hypothesis: Testable statement.
Model: An explanation of why an event occurs and how data and events are related.
Theory: A broad generalization that explains a related group of facts or processes supported by data.