Pearson Chapter 1
The properties of matter are determined by the properties of atoms and molecules.
Atoms: are submicroscopic particles that are the fundamental building blocks of ordinary matter
Molecules: Atoms bound together in specific geometrical arrangements.
Chemistry: The science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules.
Graphite and Diamonds: While both are made up of carbon, the way the atoms are arranged changes the properties to make the two.
Scientific Knowledge: Is based on observation and expermiment.
Qualitative: Noting or describing how a process happens
Quantitative: Measuring or quantifying something about the process
Hypothesis: A tentative interpretation or explanation of the observation.
Falsifiable Hypothesis: Means it makes predictions that can be confirmed or refuted by further observations.
Experiments: Hightly controlled procedures designed to generate observations that confirm or refuted a hypothesis.
Scientific Law: A brief statement that summarizes past observations and predicts future ones.
Law of conservation of mass: In a chemical reaction, matter is neither created nor destroyed - Lavoisier.
Scientific laws describe how nature behaves.
A Scientific theory: A model for the way nature is and tries to explain not merely what nature does but why.
Atomic Theory: Daltons theory that explain the law of conservation of mass. Proposing that matter is composed of small, indestructible particles called atoms. Since these particles are merely rearranged in chemical changes, the total amount of mass remains the same
Traditional View of science: It is the continual accumulation of knowledge and the noodling of increasingly precise theories.
Solid Matter:
Atoms are packed closely together each other in fixed locations
Although the atoms vibrate they do not move around or past each other
Fixed volume and ridged shape.
May be Crystalline: in which case its atoms or molecules are in patterns with long range repeated order.
Or Amorphous: in which case its atoms or molecules do not have any long-range order.
Liquid Matter:
Atoms or molecules pack about as closely as they do in solid matter
Are free to move relative to each other
A fixed volume but not a fixed shape, they assume the shape of their container
Gaseous Matter:
Atoms or molecules have a lot of space between them and are free to move relative to one another
Gases are compressible
Gases always take the shape and volume of their containers
Divisions In Classification:
A Pure Substance: Made up of only one component and its composition is invariant
Components: can be individual atoms or groups of atoms joined together.
Helium, water, and table salt are all pure substances, only made up of 1 molecule.
Mixture: is composed of two or more components in proportions that can vary from one sample to another. Example: sweet tea.
Element: A substance that cannot be chemically broken down into simpler substances
Compound: A substance composed of two or more elements in a fixed, definite proportion.
Heterogeneous Mixture: One in which the composition varies from one region of the mixture to another.
Homogeneous Mixture: One with the same composition throughout.
Decanting: A method of separating immiscible liquids by pouring the top layer into another container.
Distillation: The process by which mixtures are heated to boil off the more volatile liquid.
Volatile: Easily vaporizable
Filtration: Separating a mixture by pouring through filter paper in a funnel.
Physical changes: Changes that alter only state or appearance byt not composition
boiling water
Chemical changes: Changes that alter the composition of matter.
Rusting Iron
Physical Property: Is a property that a substance displays without changing its composition
Smell of Gasoline
Chemical property: Is a property that a substance displays only by changing its composition win a chemical change.
Corrosiveness, flammability, acidity, toxicity, and other such characteristics.