chapter 1 chem

Observation

The act of gathering data through senses or instruments.

Theory

A framework that allows us to analyze data and formulate hypotheses to understand phenomena.

Law

A principle that describes consistent results observed in data and predicts future outcomes.

Anomaly

Something that does not fit the established theories or patterns, requiring re-evaluation of those theories.

Elements

Pure substances consisting of only one type of atom.

Compounds

Substances made up of two or more different types of atoms chemically bonded together.

Mixture

A combination of two or more substances where each retains its properties.

Homogeneous mixture

A mixture with a uniform composition throughout.

Heterogeneous mixture

A mixture with a composition that varies from one region to another.

Solution

A type of homogeneous mixture where one substance is dissolved in another.

Physical properties

Characteristics that can be observed or measured without changing the substance's identity.

Chemical properties

Characteristics that describe a substance's ability to undergo chemical changes.

Physical change

An alteration in state or appearance without changing the substance's composition.

Chemical change

A transformation that results in the creation of new substances with different properties.

Law of Contradiction

The principle that contradictory statements cannot be simultaneously true.

Law of Causality

The principle that every effect has a prior cause.

Reliability of senses

The use of senses to gather data for experiments.

Ex nihilo nihil fit

A Latin phrase meaning 'out of nothing, nothing comes,' referencing the impossibility of spontaneous generation.

Aseity

The quality of being self-existent and independent.

Density

The mass of an object divided by its volume, often expressed in grams per liter (g/L).

Significant figures

Digits that carry meaning contributing to a measurement's precision.

Mole concept

A fundamental principle for counting particles by weighing, representing the amount of substance containing the same number of entities as 12 grams of carbon-12.

Scientific notation

A method for expressing very large or small numbers in a compact form, facilitating calculations.

Temperature measurement

The assessment of heat within a substance, commonly using Celsius, Fahrenheit, or Kelvin scales.