Objectives on Chem chapter 1

• Q: What is the primary focus of chemistry

A: The study of the composition, structure, and properties of matter, and the changes that matter undergoes.

• Q: What are two everyday examples of chemistry in action

A: Digesting food, synthesizing polymers for clothing, refining crude oil into gasoline, and cooking food.

• Q: What is the Scientific Method

A: A path of discovery that leads from observation and curiosity to hypothesis, experimentation, and formulation of laws or theories.

• Q: What is a Hypothesis

A: A tentative explanation of observations that acts as a guide for gathering and checking information through experimentation.

• Q: What is a Law of Science

A: A statement summarizing a vast number of experimental observations that predicts some aspect of the natural world under specific conditions.

• Q: What is a Scientific Theory

A: A well-substantiated, comprehensive, testable explanation of a particular aspect of nature that is supported by extensive experimental evidence.

• Q: What are the three domains of chemistry

A: Macroscopic domain, Microscopic domain, and Symbolic domain.

• Q: What defines the Macroscopic Domain

A: The realm of everyday things that are large enough to be sensed directly by human sight or touch (e.g., physical properties like density, solubility, flammability).

• Q: What defines the Microscopic Domain

A: The realm of matter that is too small to be seen directly, visited mostly in the imagination or through specialized instruments (e.g., atoms, molecules, ions, electrons).

• Q: What defines the Symbolic Domain

A: The specialized language used to represent components of the macroscopic and microscopic domains (e.g., chemical symbols, chemical formulas, chemical equations).

• Q: How do solids, liquids, and gases differ in shape and volume

A: Solid: Rigid, fixed shape, fixed volume. Liquid: Takes shape of container (forms flat horizontal surface), fixed volume. Gas: Expands to fill container (takes both shape and volume of container).

• Q: What is plasma

A: A gaseous state of matter containing appreciable numbers of electrically charged particles (ions and electrons), found naturally in stars or lightning.

• Q: What is the difference between mass and weight

A: Mass is a measure of the amount of matter in an object. Weight is the force exerted on an object by gravity.

• Q: What does the Law of Conservation of Mass state

A: There is no detectable change in the total quantity of matter present when matter converts from one type to another (in physical or chemical changes).

• Q: What is the difference between a pure substance and a mixture

A: A pure substance has a constant composition and identical physical properties throughout. A mixture is composed of two or more types of matter that can be present in varying amounts and separated by physical methods.

• Q: What is the difference between an element and a compound

A: An element cannot be broken down into simpler substances by chemical changes. A compound consists of two or more elements combined chemically and can be broken down into simpler substances.

• Q: What is the difference between heterogeneous and homogeneous mixtures

A: Heterogeneous mixtures have a composition that varies from point to point (e.g., oil and vinegar). Homogeneous mixtures (solutions) have a uniform composition throughout (e.g., sports drink).

• Q: What is the difference between an atom and a molecule

A: An atom is the smallest particle of an element that retains the properties of that element. A molecule consists of two or more atoms joined by chemical bonds.

• Q: What is a physical property, and what are 3 examples

A: A characteristic of matter that is not associated with a change in its chemical composition. Examples: Density, color, hardness, melting point, boiling point, electrical conductivity.

• Q: What is a physical change, and what are 2 examples

A: A change in the state or properties of matter without any change in its chemical composition. Examples: Melting wax, steam condensing into liquid water, dissolving sugar in water.

• Q: What is a chemical property, and what are 3 examples

A: The ability (or inability) of matter to change from one type of matter into another. Examples: Flammability, toxicity, acidity, reactivity with oxygen/water.

• Q: What is a chemical change, and what are 2 examples

A: A process that produces one or more types of matter that differ from the matter present before the change. Examples: Iron rusting, burning wood/matches, cooking food.

• Q: What are common indicators of a chemical change

A: Color change, evolution of a gas (bubbles), formation of a precipitate (solid), or heat/light release.

• Q: What is an extensive property

A: A property that depends on the amount of matter present (e.g., mass, volume, heat).

• Q: What is an intensive property

A: A property that does not depend on the amount of matter present (e.g., temperature, density, melting point).